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Research involving Lowell Observatory staff 2023
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Years: 2023 Bottom


  1. Duarte, J., Gonzalez-Gaitan, S., Mourao, A., et al., (including Kuehn, K.), 2023, A&A, 680, A56, A sample of dust attenuation laws for Dark Energy Survey supernova host galaxies
    Context. Type Ia supernovae (SNe Ia) are useful distance indicators in cosmology, provided their luminosity is standardized by applying empirical corrections based on light-curve properties. One factor behind these corrections is dust extinction, which is accounted for in the color-luminosity relation of the standardization. This relation is usually assumed to be universal, which can potentially introduce systematics into the standardization. The "mass step" observed for SN Ia Hubble residuals has been suggested as one such systematic.
    Aims: We seek to obtain a more complete view of dust attenuation properties for a sample of 162 SN Ia host galaxies and to probe their link to the mass step.
    Methods: We inferred attenuation laws toward hosts from both global and local (4 kpc) Dark Energy Survey photometry and composite stellar population model fits.
    Results: We recovered a relation between the optical depth and the attenuation slope, best explained by differing star-to-dust geometry for different galaxy orientations, which is significantly different from the optical depth and extinction slope relation observed directly for SNe. We obtain a large variation of attenuation slopes and confirm these change with host properties, such as the stellar mass and age, meaning a universal SN Ia correction should ideally not be assumed. Analyzing the cosmological standardization, we find evidence for a mass step and a two-dimensional "dust step", both more pronounced for red SNe. Although comparable, the two steps are not found to be completely analogous.
    Conclusions: We conclude that host galaxy dust data cannot fully account for the mass step, using either an alternative SN standardization with extinction proxied by host attenuation or a dust-step approach.

    DES-2022-069. FERMILAB-PUB-22-760-PPD.

    The DES-SN host galaxy photometric data and corresponding SN light-curve parameters are available as part of the DES3YR data release, accessible at https://www.darkenergysurvey.org/des-year-3-supernova-cosmology-results/. Cornerplots and SED fit plots for the host galaxies can be found at https://github.com/SN-CRISP/DES-SN_Host-Galaxies

  2. Webber, K., Hansen, T., Marshall, J., et al., (including Kuehn, K.), 2023, ApJ, 959, 141, Chemical Analysis of the Brightest Star of the Cetus II Ultrafaint Dwarf Galaxy Candidate
    We present a detailed chemical abundance analysis of the brightest star in the ultrafaint dwarf (UFD) galaxy candidate Cetus II from high-resolution Magellan/MIKE spectra. For this star, DES J011740.53-173053, abundances or upper limits of 18 elements from carbon to europium are derived. Its chemical abundances generally follow those of other UFD galaxy stars, with a slight enhancement of the -elements (Mg, Si, and Ca) and low neutron-capture element (Sr, Ba, and Eu) abundances supporting the classification of Cetus II as a likely UFD. The star exhibits lower Sc, Ti, and V abundances than Milky Way (MW) halo stars with similar metallicity. This signature is consistent with yields from a supernova originating from a star with a mass of ~11.2 M . In addition, the star has a potassium abundance of [K/Fe] = 0.81, which is somewhat higher than the K abundances of MW halo stars with similar metallicity, a signature that is also present in a number of UFD galaxies. A comparison including globular clusters and stellar stream stars suggests that high K is a specific characteristic of some UFD galaxy stars and can thus be used to help classify objects as UFD galaxies. * This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.
  3. Kareta, T., Thomas, C., Li, J., et al., (including Moskovitz, N., Polakis, T., Skiff, B.), 2023, ApJL, 959, L12, Ejecta Evolution Following a Planned Impact into an Asteroid: The First Five Weeks
    The impact of the Double Asteroid Redirection Test spacecraft into Dimorphos, moon of the asteroid Didymos, changed Dimorphos's orbit substantially, largely from the ejection of material. We present results from 12 Earth-based facilities involved in a world-wide campaign to monitor the brightness and morphology of the ejecta in the first 35 days after impact. After an initial brightening of ~1.4 mag, we find consistent dimming rates of 0.11-0.12 mag day-1 in the first week, and 0.08-0.09 mag day-1 over the entire study period. The system returned to its pre-impact brightness 24.3-25.3 days after impact though the primary ejecta tail remained. The dimming paused briefly eight days after impact, near in time to the appearance of the second tail. This was likely due to a secondary release of material after re-impact of a boulder released in the initial impact, though movement of the primary ejecta through the aperture likely played a role.
  4. Chandler, C., Oldroyd, W., Trujillo, C., et al., (including Kueny, J.), 2023, RNAAS, 7, 271, New Active Jupiter Family Comet 2008 QZ44: a Discovery with Citizen Science
    We report our discovery of cometary activity in the form of a diffuse tail associated with minor planet 2008 QZ44 during two previous orbits: 2008 and 2017. This finding was prompted in part by Active Asteroids, our Zooniverse-hosted NASA Partner Citizen Science program. Participants flagged two UT 2017 July 12 Dark Energy Camera images of 2008 QZ44 as active. Independently, our team identified activity in nine Canada-France-Hawaii Telescope MegaPrime images from UT 2008 November 20. During both apparitions 2008 QZ44 was near its perihelion passage. 2008 QZ44 has a Tisserand parameter with respect to Jupiter of 2.821, placing it in the Jupiter-family comet (JFC) class, and our dynamical integrations confirm this classification. JFCs contain primordial material that informs us about solar system evolution, and help us map the present-day volatile distribution. We note that 2008 QZ44 has previously been classified as a quasi-Hilda comet candidate.
  5. Chandler, C., Oldroyd, W., Trujillo, C., et al., (including Kueny, J.), 2023, RNAAS, 7, 279, Mars-Crossing Minor Planet 2018 VL10: a Jupiter-family Comet Discovery via Citizen Science
    We announce the discovery of cometary activity emitting from minor planet 2018 VL10 in Dark Energy Camera images spanning from UT 2018 December 31 to UT 2019 March 3. The activity was identified by volunteers of our NASA Partner program Active Asteroids, a Zooniverse-hosted Citizen Science project designed to find previously unknown activity in known minor planets. Notably, 2018 VL10 crosses the orbits of Mars and Jupiter, and experiences close approaches of less than 0.5 au with both Earth and Jupiter. We classify 2018 VL10 as a member of the Jupiter-family comets, a group of objects especially important to understand because they hold important clues about the solar system volatile distribution, past and present.
  6. Polishook, D., DeMeo, F., Burt, B., et al., 2023, PSJ, 4, 229, Near-IR Spectral Observations of the Didymos System: Daily Evolution Before and After the DART Impact Indicates that Dimorphos Originated from Didymos
    Ejecta from Dimorphos following the DART mission impact significantly increased the brightness of the Didymos-Dimorphos system, allowing us to examine subsurface material. We report daily near-IR spectroscopic observations of the Didymos system using NASA's IRTF that follow the evolution of the spectral signature of the ejecta cloud over 1 week, from 1 day before the impact. Overall, the spectral features remained fixed (S-type classification) while the ejecta dissipated, confirming that both Didymos and Dimorphos are constructed from the same silicate material. This novel result strongly supports binary asteroid formation models that include the breaking up of a single body due to rotational breakup of kilometer-wide bodies. At impact time +14 and +38 hr, the spectral slope decreased, but the following nights presented an increasing spectral slope that almost returned to the preimpact slope. However, the parameters of the 1 m band remained fixed, and no "fresh"/Q-type-like spectrum was measured. We interpret this as follows. (1) The ejecta cloud is the main contributor (60%-70%) to the overall light during the ~40 hr after impact. (2) Coarser debris (100 m) dominated the ejecta cloud, decreasing the spectral slope (after radiation pressure removed the fine grains 10 hr after impact). (3) After approximately 1 week, the ejecta cloud dispersed enough to make the fine grains on Didymos's surface the dominant part of the light, increasing the spectral slope to the preimpact level. (4) A negligible amount of nonweathered material was ejected from Dimorphos's subsurface, suggesting that Dimorphos was accumulated from weathered material ejected from Didymos's surface.
  7. DeSpain, J., Chandler, C., Oldroyd, W., et al., (including Kueny, J.), 2023, RNAAS, 7, 257, Citizen Science Discovery of a Recurrently Active Jupiter-Family Comet: (551023) 2012 UQ192
    We have discovered evidence of cometary activity originating from (551023) 2012 UQ192 (alternately designated 2019 SN40), which we dynamically classify as a Jupiter Family Comet (JFC). JFCs have eccentric Jupiter-crossing orbits and originate in the Kuiper Belt. Analysis of these objects can provide vital information about minor planets in the outer solar system, such as the distribution of volatiles within the solar system. Activity on 2012 UQ192 was first recognized by volunteers on our NASA Partner Citizen Science project Active Asteroids. Through our own examination of archival image data, we found a total of ~30 images presenting strong evidence of activity near perihelion during two separate orbits. 2012 UQ192 is notable as we found it to be recurrently active. When 2012 UQ192 approaches its perihelion passage in 2027 September, we predict it will reactivate and will be a prime subject for follow-up observations.
  8. Baines, E., Clark, J., Schmitt, H., et al., (including von Braun, K.), 2023, AJ, 166, 268, 33 New Stellar Angular Diameters from the NPOI, and Nearly 180 NPOI Diameters as an Ensemble
    We present new angular diameter measurements for 33 stars from the Navy Precision Optical Interferometer, reaching uncertainties on the limb-darkened diameter of 2% or less for 21 targets. We also determined the physical radius, bolometric flux, luminosity, and effective temperature for each star. Our sample is a mix of giant, subgiant, and dwarf stars, and span spectral classes from mid-A to to mid-K. We combined these 33 stars with samples from previous publications to analyze how the NPOI diameters compare to those obtained using other means, namely (V - K) color, the JMMC Stellar Diameters Catalog, and Gaia predictions.
  9. Toy, M., Wiseman, P., Sullivan, M., et al., (including Kuehn, K.), 2023, MNRAS, 526, 5292, Rates and properties of Type Ia supernovae in galaxy clusters within the dark energy survey
    We identify 66 photometrically classified Type Ia supernovae (SNe Ia) from the Dark Energy Survey (DES) that have occurred within red-sequence selected galaxy clusters. We compare light-curve and host galaxy properties of the cluster SNe to 1024 DES SNe Ia located in field galaxies, the largest comparison of two such samples at high redshift (z > 0.1). We find that cluster SN light curves decline faster than those in the field (97.7 per cent confidence). However, when limiting these samples to host galaxies of similar colour and mass, there is no significant difference in the SN light-curve properties. Motivated by previous detections of a higher-normalized SN Ia delay-time distribution in galaxy clusters, we measure the intrinsic rate of SNe Ia in cluster and field environments. We find the average ratio of the SN Ia rate per galaxy between high-mass ($10\le \log \mathrm{(\mathit{ M}_{*}/{\rm \mathit{ M}}_{\odot })} \le 11.25$) cluster and field galaxies to be 0.594 0.068. This difference is mass-dependent, with the ratio declining with increasing mass, which suggests that the stellar populations in cluster hosts are older than those in field hosts. We show that the mass-normalized rate (or SNe per unit mass) in massive-passive galaxies is consistent between cluster and field environments. Additionally, both of these rates are consistent with rates previously measured in clusters at similar redshifts. We conclude that in massive-passive galaxies, which are the dominant hosts of cluster SNe, the cluster delay-time distribution is comparable to the field.
  10. Anbajagane, D., Chang, C., Banerjee, A., et al., (including Kuehn, K.), 2023, MNRAS, 526, 5530, Beyond the 3rd moment: a practical study of using lensing convergence CDFs for cosmology with DES Y3
    Widefield surveys probe clustered scalar fields - such as galaxy counts, lensing potential, etc. - which are sensitive to different cosmological and astrophysical processes. Constraining such processes depends on the statistics that summarize the field. We explore the cumulative distribution function (CDF) as a summary of the galaxy lensing convergence field. Using a suite of N-body light-cone simulations, we show the CDFs' constraining power is modestly better than the second and third moments, as CDFs approximately capture information from all moments. We study the practical aspects of applying CDFs to data, using the Dark Energy Survey (DES Y3) data as an example, and compute the impact of different systematics on the CDFs. The contributions from the point spread function and reduced shear approximation are $\lesssim 1~{{\ \rm per\ cent}}$ of the total signal. Source clustering effects and baryon imprints contribute 1-10 per cent. Enforcing scale cuts to limit systematics-driven biases in parameter constraints degrade these constraints a noticeable amount, and this degradation is similar for the CDFs and the moments. We detect correlations between the observed convergence field and the shape noise field at 13. The non-Gaussian correlations in the noise field must be modelled accurately to use the CDFs, or other statistics sensitive to all moments, as a rigorous cosmology tool.
  11. Reuter, D., Simon, A., Lunsford, A., et al., (including Grundy, W.), 2023, SSRv, 219, 69, L'Ralph: A Visible/Infrared Spectral Imager for the Lucy Mission to the Trojans
    The Lucy Mission to the Trojan asteroids in Jupiter's orbit carries an instrument named L'Ralph, a visible/near infrared multi-spectral imager and a short wavelength infrared hyperspectral imager. It is one of the core instruments on Lucy, NASA's first mission to the Trojans. L'Ralph's primary purpose is to map the surface geology and composition of these objects, but it will also be used to search for possible tenuous exospheres. It is compact, low mass (32.3 kg), power efficient (24.5 W), and robust with high sensitivity and excellent imaging. These characteristics, and its high degree of redundancy, make L'Ralph ideally suited to this long-duration multi-flyby reconnaissance mission.
  12. Sickafoose, A., Levine, S., Bosh, A., et al., 2023, PSJ, 4, 221, Material around the Centaur (2060) Chiron from the 2018 November 28 UT Stellar Occultation
    A stellar occultation of Gaia DR3 2646598228351156352 by the Centaur (2060) Chiron was observed from the South African Astronomical Observatory on 2018 November 28 UT. Here we present a positive detection of material surrounding Chiron from the 74-inch telescope for this event. Additionally, a global atmosphere is ruled out at the tens of microbars level for several possible atmospheric compositions. There are multiple 3 drops in the 74-inch light curve: three during immersion and two during emersion. Occulting material is located between 242 and 270 km from the center of the nucleus in the sky plane. Assuming the ring-plane orientation proposed for Chiron from the 2011 occultation, the flux drops are located at 352, 344, and 316 km (immersion) and 357 and 364 km (emersion) from the center, with normal optical depths of 0.26, 0.36, and 0.22 (immersion) and 0.26 and 0.18 (emersion) and equivalent widths between 0.7 and 1.3 km. This detection is similar to the previously proposed two-ring system and is located within the error bars of that ring-pole plane; however, the normal optical depths are less than half of the previous values, and three features are detected on immersion. These results suggest that the properties of the surrounding material have evolved between the 2011, 2018, and 2022 observations.
  13. Sanborn, J., Chambers, K., de Boer, T., et al., 2023, MPEC, 2023-W90, 2021 OX
    No abstract found.
  14. do Nascimento, J., Barnes, S., Saar, S., et al., (including Hall, J.), 2023, ApJ, 958, 57, A Hale-like Cycle in the Solar Twin 18 Scorpii
    Characterizing the cyclic magnetic activity of stars that are close approximations of our Sun offers our best hope for understanding our Sun's current and past magnetism, the space weather around solar-type stars, and more generally, the dynamos of other cool stars. The nearest current approximation to the Sun is the solar twin 18 Scorpii, a naked-eye Sun-like star of spectral type G2 Va. However, while 18 Scorpii's physical parameters closely match those of the Sun, its activity cycle is about 7 yr, and shorter than the solar cycle. We report the measurement of a periodicity of 15 yr that corresponds to a longer activity cycle for 18 Scorpii based on observations extending to the last three decades. The global magnetic geometry of 18 Scorpii changes with this 15 yr cycle and appears to be equivalent to the solar 22 yr magnetic polarity cycle. These results suggest that 18 Scorpii is also a magnetic proxy for a younger Sun, adding an important new datum for testing dynamo theory and magnetic evolution of low-mass stars. The results perturb our understanding of the relationship between cycle and rotation, constrain the Sun's magnetism and the Sun-Earth connection over the past billion years, and suggest that solar Schwabe and Hale cycle periods have increased over that time span.
  15. Asaki, Y., Maud, L., Francke, H., et al., (including Fernandez, J.), 2023, ApJ, 958, 86, ALMA High-frequency Long Baseline Campaign in 2021: Highest Angular Resolution Submillimeter Wave Images for the Carbon-rich Star R Lep
    The Atacama Large Millimeter/submillimeter Array (ALMA) was used in 2021 to image the carbon-rich evolved star R Lep in Bands 8-10 (397-908 GHz) with baselines up to 16 km. The goal was to validate the calibration, using band-to-band (B2B) phase referencing with a close phase calibrator J0504-1512, 1.2 from R Lep in this case, and the imaging procedures required to obtain the maximum angular resolution achievable with ALMA. Images of the continuum emission and the hydrogen cyanide (HCN) maser line at 890.8 GHz, from the J = 10-9 transition between the (1110) and (0400) vibrationally excited states, achieved angular resolutions of 13, 6, and 5 mas in Bands 8-10, respectively. Self-calibration (self-cal) was used to produce ideal images to compare with the B2B phase referencing technique. The continuum emission was resolved in Bands 9 and 10, leaving too little flux for the self-cal of the longest baselines, so these comparisons are made at coarser resolution. Comparisons showed that B2B phase referencing provided phase corrections sufficient to recover 92%, 83%, and 77% of the ideal image continuum flux densities. The HCN maser was sufficiently compact to obtain self-cal solutions in Band 10 for all baselines (up to 16 km). In Band 10, B2B phase referencing as compared to the ideal images recovered 61% and 70% of the flux density for the HCN maser and continuum, respectively.
  16. Marciniak, A., Durech, J., Choukroun, A., et al., (including Skiff, B.), 2023, A&A, 679, A60, Scaling slowly rotating asteroids with stellar occultations
    Context. As evidenced by recent survey results, the majority of asteroids are slow rotators (spin periods longer than 12 h), but lack spin and shape models because of selection bias. This bias is skewing our overall understanding of the spins, shapes, and sizes of asteroids, as well as of their other properties. Also, diameter determinations for large (>60 km) and medium-sized asteroids (between 30 and 60 km) often vary by over 30% for multiple reasons.
    Aims: Our long-term project is focused on a few tens of slow rotators with periods of up to 60 h. We aim to obtain their full light curves and reconstruct their spins and shapes. We also precisely scale the models, typically with an accuracy of a few percent.
    Methods: We used wide sets of dense light curves for spin and shape reconstructions via light-curve inversion. Precisely scaling them with thermal data was not possible here because of poor infrared datasets: large bodies tend to saturate in WISE mission detectors. Therefore, we recently also launched a special campaign among stellar occultation observers, both in order to scale these models and to verify the shape solutions, often allowing us to break the mirror pole ambiguity.
    Results: The presented scheme resulted in shape models for 16 slow rotators, most of them for the first time. Fitting them to chords from stellar occultation timings resolved previous inconsistencies in size determinations. For around half of the targets, this fitting also allowed us to identify a clearly preferred pole solution from the pair of two mirror pole solutions, thus removing the ambiguity inherent to light-curve inversion. We also address the influence of the uncertainty of the shape models on the derived diameters.
    Conclusions: Overall, our project has already provided reliable models for around 50 slow rotators. Such well-determined and scaled asteroid shapes will, for example, constitute a solid basis for precise density determinations when coupled with mass information. Spin and shape models in general continue to fill the gaps caused by various biases.

    Lighcurves are available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr ( or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/679/A60

  17. Chandler, C., Oldroyd, W., Trujillo, C., et al., (including Kueny, J.), 2023, RNAAS, 7, 237, New Active Quasi-Hilda Asteroid 2004 CV50: A Citizen Science Discovery
    We report that minor planet 2004 CV50 displayed cometary activity in the form of a short, diffuse tail, first identified by volunteers of the Citizen Science program Active Asteroids, a NASA Partner program hosted on the Zooniverse online platform. The activity is present in three images, from UT 2020 February 15 and UT 2020 March 14, that were acquired with the Dark Energy Camera on the Blanco 4 m telescope at the Cerro-Tololo Inter-American Observatory in Chile. We find that 2004 CV50 is most likely an active quasi-Hilda object rather than an active asteroid, despite 2004 CV50 having a Tisserand parameter with respect to Jupiter of 3.06.
  18. Bernardinelli, P., Bernstein, G., Jindal, N., et al., (including Kuehn, K.), 2023, ApJS, 269, 18, Photometry of Outer Solar System Objects from the Dark Energy Survey. I. Photometric Methods, Light-curve Distributions, and Trans-Neptunian Binaries
    We report the methods of and initial scientific inferences from the extraction of precision photometric information for the >800 trans-Neptunian objects (TNOs) discovered in the images of the Dark Energy Survey (DES). Scene-modeling photometry is used to obtain shot-noise-limited flux measures for each exposure of each TNO, with background sources subtracted. Comparison of double-source fits to the pixel data with single-source fits are used to identify and characterize two binary TNO systems. A Markov Chain Monte Carlo method samples the joint likelihood of the intrinsic colors of each source as well as the amplitude of its flux variation, given the time series of multiband flux measurements and their uncertainties. A catalog of these colors and light-curve amplitudes A is included with this publication. We show how to assign a likelihood to the distribution q(A) of light-curve amplitudes in any subpopulation. Using this method, we find decisive evidence (i.e., evidence ratio <0.01) that cold classical (CC) TNOs with absolute magnitude 6 < H r < 8.2 are more variable than the hot classical (HC) population of the same H r , reinforcing theories that the former form in situ and the latter arise from a different physical population. Resonant and scattering TNOs in this H r range have variability consistent with either the HCs or CCs. DES TNOs with H r < 6 are seen to be decisively less variable than higher-H r members of any dynamical group, as expected. More surprising is that detached TNOs are decisively less variable than scattering TNOs, which requires them to have distinct source regions or some subsequent differential processing.
  19. Oldroyd, W., Chandler, C., Trujillo, C., et al., (including Kueny, J.), 2023, ApJL, 957, L1, Recurring Activity Discovered on Quasi-Hilda 2009 DQ118
    We have discovered two epochs of activity on quasi-Hilda 2009 DQ118. Small bodies that display comet-like activity, such as active asteroids and active quasi-Hildas, are important for understanding the distribution of water and other volatiles throughout the solar system. Through our NASA Partner Citizen Science project, Active Asteroids, volunteers classified archival images of 2009 DQ118 as displaying comet-like activity. By performing an in-depth archival image search, we found over 20 images from UT 2016 March 8-9 with clear signs of a comet-like tail. We then carried out follow-up observations of 2009 DQ118 using the 3.5 m Astrophysical Research Consortium Telescope at Apache Point Observatory, Sunspot, New Mexico, USA and the 6.5 m Magellan Baade Telescope at Las Campanas Observatory, Chile. These images revealed a second epoch of activity associated with the UT 2023 April 22 perihelion passage of 2009 DQ118. We performed photometric analysis of the tail and find that it had a similar apparent length and surface brightness during both epochs. We also explored the orbital history and future of 2009 DQ118 through dynamical simulations. These simulations show that 2009 DQ118 is currently a quasi-Hilda and that it frequently experiences close encounters with Jupiter. We find that 2009 DQ118 is currently on the boundary between asteroidal and cometary orbits. Additionally, it has likely been a Jupiter family comet or Centaur for much of the past 10 kyr and will be in these same regions for the majority of the next 10 kyr. Since both detected epochs of activity occurred near perihelion, the observed activity is consistent with sublimation of volatile ices. 2009 DQ118 is currently observable until ~mid-October 2023. Further observations would help to characterize the observed activity.
  20. Zhou, C., Tong, A., Troxel, M., et al., (including Kuehn, K.), 2023, MNRAS, 526, 323, The intrinsic alignment of red galaxies in DES Y1 redMaPPer galaxy clusters
    Clusters of galaxies trace the most non-linear peaks in the cosmic density field. The weak gravitational lensing of background galaxies by clusters can allow us to infer their masses. However, galaxies associated with the local environment of the cluster can also be intrinsically aligned due to the local tidal gradient, contaminating any cosmology derived from the lensing signal. We measure this intrinsic alignment in Dark Energy Survey (DES) Year 1 REDMAPPER clusters. We find evidence of a non-zero mean radial alignment of galaxies within clusters between redshifts 0.1-0.7. We find a significant systematic in the measured ellipticities of cluster satellite galaxies that we attribute to the central galaxy flux and other intracluster light. We attempt to correct this signal, and fit a simple model for intrinsic alignment amplitude (AIA) to the measurement, finding AIA = 0.15 0.04, when excluding data near the edge of the cluster. We find a significantly stronger alignment of the central galaxy with the cluster dark matter halo at low redshift and with higher richness and central galaxy absolute magnitude (proxies for cluster mass). This is an important demonstration of the ability of large photometric data sets like DES to provide direct constraints on the intrinsic alignment of galaxies within clusters. These measurements can inform improvements to small-scale modelling and simulation of the intrinsic alignment of galaxies to help improve the separation of the intrinsic alignment signal in weak lensing studies.
  21. Pace, A., Koposov, S., Walker, M., et al., (including Kuehn, K.), 2023, MNRAS, 526, 1075, The kinematics, metallicities, and orbits of six recently discovered Galactic star clusters with Magellan/M2FS spectroscopy
    We present Magellan/M2FS spectroscopy of four recently discovered Milky Way star clusters (Gran 3/Patchick 125, Gran 4, Garro 01, and LP 866) and two newly discovered open clusters (Gaia 9 and Gaia 10) at low Galactic latitudes. We measure line-of-sight velocities and stellar parameters ([Fe/H], log g, Teff, and [Mg/Fe]) from high-resolution spectroscopy centred on the Mg triplet and identify 20-80 members per star cluster. We determine the kinematics and chemical properties of each cluster and measure the systemic proper motion and orbital properties by utilizing Gaia astrometry. We find Gran 3 to be an old, metal-poor (mean metallicity of [Fe/H] = -1.83) globular cluster located in the Galactic bulge on a retrograde orbit. Gran 4 is an old, metal-poor ([Fe/H] = -1.84) globular cluster with a halo-like orbit that happens to be passing through the Galactic plane. The orbital properties of Gran 4 are consistent with the proposed LMS-1/Wukong and/or Helmi streams merger events. Garro 01 is metal-rich ([Fe/H] = -0.30) and on a near-circular orbit in the outer disc but its classification as an open cluster or globular cluster is ambiguous. Gaia 9 and Gaia 10 are among the most distant known open clusters at $R_{\mathrm{GC}}\sim 18,~21.2~\mathrm{\, kpc}$ and most metal-poor with [Fe/H] ~-0.50, -0.34 for Gaia 9 and Gaia 10, respectively. LP 866 is a nearby, metal-rich open cluster ([Fe/H] = +0.10). The discovery and confirmation of multiple star clusters in the Galactic plane shows the power of Gaia astrometry and the star cluster census remains incomplete.
  22. Sanchez, C., Alarcon, A., Bernstein, G., et al., (including Kuehn, K.), 2023, MNRAS, 525, 3896, The Dark Energy Survey Year 3 high-redshift sample: selection, characterization, and analysis of galaxy clustering
    The fiducial cosmological analyses of imaging surveys like DES typically probe the Universe at redshifts z < 1. We present the selection and characterization of high-redshift galaxy samples using DES Year 3 data, and the analysis of their galaxy clustering measurements. In particular, we use galaxies that are fainter than those used in the previous DES Year 3 analyses and a Bayesian redshift scheme to define three tomographic bins with mean redshifts around z ~ 0.9, 1.2, and 1.5, which extend the redshift coverage of the fiducial DES Year 3 analysis. These samples contain a total of about 9 million galaxies, and their galaxy density is more than 2 times higher than those in the DES Year 3 fiducial case. We characterize the redshift uncertainties of the samples, including the usage of various spectroscopic and high-quality redshift samples, and we develop a machine-learning method to correct for correlations between galaxy density and survey observing conditions. The analysis of galaxy clustering measurements, with a total signal to noise S/N ~ 70 after scale cuts, yields robust cosmological constraints on a combination of the fraction of matter in the Universe m and the Hubble parameter h, $\Omega _m h = 0.195^{+0.023}_{-0.018}$, and 2-3 per cent measurements of the amplitude of the galaxy clustering signals, probing galaxy bias and the amplitude of matter fluctuations, b8. A companion paper (in preparation) will present the cross-correlations of these high-z samples with cosmic microwave background lensing from Planck and South Pole Telescope, and the cosmological analysis of those measurements in combination with the galaxy clustering presented in this work.
  23. Trujillo, C., Chandler, C., Oldroyd, W., et al., (including Kueny, J.), 2023, DPS, 55, 102.02, Cometary Activity on Quasi-Hilda Object 2018 CZ16
    We present the discovery of activity originating from quasi-Hilda object 2018 CZ16, a finding stemming from the Citizen Science project ActiveAsteroids.net , which has employed over 8,000 participants to make over 6 million image classifications. For 2018 CZ16, we identified a broad (encompassing about a 60 angle) but short (extending about 5 arcseconds in length) tail in archival Dark Energy Camera images (Blanco 4-m Cerro Tololo Inter-American Observatory, Chile) from UT 2018 May 15, 17 and 18. Activity occurred 2 months prior to perihelion, consistent with sublimation-driven activity. Objects with recurrent activity associated with perihelion are suspected to be driven by water ice and their presence sheds light on the volatile distribution in the solar system. To date, we have found only one epoch of activity for 2018 CZ16 near perihelion, but we encourage future observations of the object to identify whether the activity is recurrent. 2018 CZ16 comes to perihelion in late 2024 and approaches opposition in mid 2025, when it is a prime target for southern hemisphere observations. This work was supported by NASA grants 80NSSC19K0869 and 80NSSC21K0114.
  24. Martin, A., Emery, J., Wong, I., et al., (including Grundy, W.), 2023, DPS, 55, 107.04, Observations of Lucy's Trojan Targets with JWST MIRI
    Jupiter Trojan asteroids (hereafter, Trojans) are a key small body population found in Jupiter's L4 and L5 Lagrange points and are dynamically stable over the lifetime of the Solar System. These primitive asteroids link together formation theories and dynamical models that explain how our Solar System formed. Trojans share important characteristics with the dynamically excited Kuiper Belt populations and Neptunian Trojans. As such, Trojans may be one of the most accessible examples of the planetesimals that populated the outer protoplanetary disk. Mid-Infrared (MIR; 5-35 m) spectral analysis of fourteen Trojans indicates their regoliths are dominated by fine-particulate amorphous and crystalline silicates, and is consistent with outer solar system formation theories. However, the low albedos and generally featureless global near infrared (NIR; 0.7 2.5 m) spectra leave these objects mysterious still. Furthermore, the number of Trojans observed in the MIR remains extremely low compared to NIR observations. The Lucy mission, which launched in October of 2022, will be the first to explore the Trojan asteroids. Over the next ten years, Lucy will perform flybys of (3548) Eurybates, (15094) Polymele, (11351) Leucus, (21900) Orus, and (617) Patroclus and its binary Menoetius. MIR observations of the Lucy targets in concert with the Lucy mission will illuminate the Trojan's dynamic history and current mineralogy. Leucus, Orus, Eurybates, Polymele, and Patroclus were observed by the James Webb Space Telescope (JWST) with Mid-Infrared Instrument (MIRI) in Medium Resolution spectroscopy (MRS) mode as part of the Cycle 1 GO program 2574 (PI M. Brown) on Nov. 15th, 2022 (10:31 11:52 UT), Feb. 23rd, 2023 (8:50-10:32 UT), March 21st, 2023 (17:26 18:43 UT), March 30th, 2023 (17:01 22:28 UT), and July 1st, 2023 (8:49-10:54 UT) respectively. MIRI MRS observations cover the ~5 27.9 spectral range, which will not be acquired by instruments on the Lucy spacecraft. We will present MIR spectra of Eurybates, Polymele, Leucus, Orus, and Patroclus and the results of our Near-Earth Asteroid Thermal Model (NEATM). Additionally, we compare JWST spectra of Eurybates and Patroclus to previously observed MIR spectra taken with the Spitzer Space Telescope. We will derive silicate mineralogy and compare their compositions to other dynamically linked small body populations (e.g., Neptune Trojans).
  25. Blakley, B., Grundy, W., Tegler, S., et al., 2023, DPS, 55, 114.08, Study of Uranian Satellite Volatiles
    Non-water ices and non-water volatiles have been spectroscopically observed in the outer solar system and in comet comae. The presence of ammonia (NH3) and ammonia hydrates on satellites in the Uranian system, such as Oberon, Titania, Ariel, and Umbriel, has been predicted (and observed, in the case of the latter two moons),1,2 and may increase the likelihood of the existence of subsurface oceans on these worlds.3 Castillo-Rogez et al. show that high accretion of CO2- and NH3-ices on dwarf planets and icy moons create stronger magnetic fields than would be expected from subsurface oceans of pure water.4 Additionally, the high volatility of oxygen makes the observed abundance of O2-ice in comet comae and on the surface of Ganymede puzzling. However, for many species of volatiles, which are observed or hypothesized on icy satellites and Kuiper Belt Objects, the assumed vapor pressures have been extrapolated from laboratory studies at much higher temperatures and pressures than are appropriate for the surface conditions of these bodies.5 In the Astrophysical Materials Laboratory at Northern Arizona University, we have investigated the vapor pressures of several species, including NH3, CO2, and O2, at temperatures applicable for surface conditions for the Uranian system, and relevant for the Neptunian system, as well as other planetary bodies in the outer Solar System. Our results show that these species are stable as ices at higher temperatures than expected from previous thermodynamic models, which may have implications for the stability of non-water ices on icy bodies. Acknowledgements: This work is supported in part by the NAU REU program under NSF grant 1950901. References: [1] R. J. Cartwright et al. (2020) Astrophysical Journal Letters, 898(1), L22. [2] R. J. Cartwright et al. (2023), The Planetary Science Journal, 4(3), 42. [3] C. J. Bierson & F. Nimmo (2022) Icarus, 373, 114776. [4] J. C. Castillo-Rogez et al. (2022) Geophysical Research Letters, 49(16), e2021GL097256. [5] N. Fray and B. Schmitt (2009) Planetary and Space Science, 57(14-15), 2053-2080.
  26. Chandler, C., Oldroyd, W., Trujillo, C., et al., (including Kueny, J.), 2023, DPS, 55, 115.02, The "Active Asteroids" Citizen Science Program: Two Years of Discovery
    Launched in August 2021, our NASA Partner program "Active Asteroids" (http://activeasteroids.net) is a Citizen Science project that engages the public in our endeavor to identify asteroids with comet-like features, such as tails or comae, known as active asteroids. Active asteroids are rare, with just 50 found thus far among the roughly 1.1 million asteroids identified to date. Despite their paucity, active asteroids further our understanding of astrophysical processes at play in the solar system (e.g., volatile sublimation) and, crucially, help describe the distribution of ices throughout the solar system, knowledge important to astrobiology and for future space exploration. In our project we ask volunteers to search for evidence of cometary activity in images of known minor planets we extract from publicly available Dark Energy Camera data. This task is impractical for our team to carry out on our own due to the large volume of data. In the two years since our program began on the Zooniverse platform, over 8,000 volunteers have helped us identify numerous previously unknown active objects, including active asteroids, active quasi-Hildas, and Jupiter Family Comets. Moreover, participant efforts have unexpectedly led us to discoveries about objects already known to be active. Here, we (1) describe the ongoing Active Asteroids campaign, (2) detail results from the project, and (3) discuss insights from our program that may be of practical use to the broader Citizen Science community. This material is based upon work supported by the NSF Graduate Research Fellowship Program under grant No. 2018258765 and grant No. 2020303693. C.O.C., H.H.H., and C.A.T. acknowledge support from NASA grant 80NSSC19K0869. W.J.O. and C.A.T. acknowledge support from NASA grant 80NSSC21K0114. W.A.B. was supported in part by NSF award 1950901. This work is funded in part through the LSST Interdisciplinary Network for Collaboration for Computing (LINCC) Frameworks. LINCC Frameworks is supported by Schmidt Futures, a philanthropic initiative founded by Eric and Wendy Schmidt, as part of the Virtual Institute of Astrophysics (VIA).
  27. Benecchi, S., Hammel, H., Grundy, W., et al., 2023, DPS, 55, 115.04, Outreach Observations of Uranus and Neptune in support of NASA's New Horizons Mission
    NASA's New Horizons (NH) spacecraft observed Uranus and Neptune from its position in the outer solar system (>56 au) in September 2023 at high phase angles not otherwise attainable, concurrent with HST. The NH Project solicited simultaneous observations by the global amateur astronomy community to support this event. NH observed Uranus from 12:15 UT on Sept. 16 6:27 UT on Sept. 17 (17.2 hours) and Neptune from 7:35 UT on Sept. 22 16:59 UT on Sept. 23 (32.4 hours). Viewed from NH, the observation phase angles were 43 and 80, respectively. These NH data provide new insights into the atmospheric radiation balance of both planets and are also geometrically similar to many exoplanet studies from ground- and Earth-orbit facilities. Key questions NH seeks to address with these observations include: What are the energy budgets and heat balances for each of these planets and what roles do water and convection play in their atmospheres? What fraction of incident sunlight does each planet absorb and how does this compare with the thermal energy each planet emits? While NH did not spatially resolve these planets, the new data significantly reduce uncertainties in the Voyager solar phase curve, while providing additional red/blue wavelength discrimination; the NH Multispectral Visible Imaging Camera (MVIC) extends observations to 0.98 m. Concurrent observations from Earth at low phase angles (<3) even the week before and after spacecraft observations from relatively modest 0.3-0.5-m class telescopes, can produce images that reveal atmospheric structure on these distant worlds. These contemporaneous observations will help break degeneracies in how the atmospheric aerosols scatter, better constraining their size and optical depth and reducing the number of free parameters. The observations of Uranus could include measuring the current brightness distribution across the planet, as well as the possible presence of discrete clouds. For Neptune, they include characterizing unusually bright features. They also provide a better temporal baseline for and even help interpret the originating mechanism(s) for structure in the NH and HST measurements. The NH observations of Uranus and Neptune will be downlinked later in 2023; here we report on the participation to date from the amateur community.
  28. Lierle, P., Schmidt, C., Lovett, E., et al., (including Llama, J.), 2023, DPS, 55, 116.10, Measurement of Heating in Mercury's Alkali Exotail
    With R~150,000 resolving power and fast tip-tilt image stabilization, the Extreme Precision Spectrometer at the 4.3m Lowell Discovery Telescope is ideally suited for measuring line broadening in planetary gases (Jurgenson et al. 2016; Petersburg et al. 2020; Brewer et al. 2020). Here we present measurements sampling between 0 and 5 planetary radii along the cometlike tail of Mercury's sodium and potassium exosphere. Data were obtained surrounding maximum radiation pressure and at a 90 phase angle, where Mercury's tail is oriented perpendicular to the line of sight. Spectra show steadily broadening linewidths in both sodium and potassium with distance from the planet. Effective temperature estimates are obtained by convolving a model of the Doppler-broadened hyperfine structure with the instrumental line spread function. The result is a dramatic heating in sodium gas from ~1,200 K to nearly 10,000 K as the gas is sampled from 0 to 5 Mercury radii downtail. Potassium effective temperatures over this range show an even greater increase from ~700 K to 11,000 K. Small-scale effective temperature variations are also seen on Mercury's dayside with sodium at high latitudes being 100-200 K hotter than gas at the sub-solar point. We theorize that this heating results from the recoil of photon momenta as light is re-emitted from the excited atoms. Photon re-emission is nearly isotropic in alkali D line transitions, and while direction vectors cancel on average, recoil events could still heat the gas by imparting a momentum of / onto each atom at a variable resonance scattering rate. Due to radiation pressure, resonance scattering rates increase down-tail since the incident sunlight available to excite the gases Doppler shifts from the Fraunhofer absorption wells into the solar continuum. As atoms move down-tail with Mercury in the outbound portion of its orbit, there is positive feedback in the scattering rate and each photon scatter imparts its momentum, steadily heating the population in a random-walk. The observed difference between sodium and potassium heating supports this theory: heating would scale with radiation pressure, which is nearly 50% higher in potassium. Observations have not yet been made at the inbound leg of Mercury's orbit where negative feedback occurs, however, and numerical modelling is needed to test this hypothesis. This heating mechanism is previously unconsidered in dynamical models of escaping planetary atmospheres. The finding has broad implications to collisionless gas dynamics and is relevant to studies of the lunar exosphere, cometary comae and exoplanetary transit spectra.
  29. Stern, S., White, O., Grundy, W., et al., 2023, DPS, 55, 202.01, The Properties and Origin of Kuiper Belt Object Arrokoth's Large Mounds
    We report on a study of the large mounds that dominate the appearance of New Horizons flyby target Kuiper Belt Object (KBO) (486958) Arrokoth's larger lobe, named Wenu. We also find evidence of several crypto-mounds on KBO Arrokoth's smaller lobe, Weeyo, whose present appearance has been affected by for formation of its largest crater, called Sky. We compare the geological context of Wenu's mounds, and measure and intercompare their shapes, sizes/orientations, reflectance, and colors. We find that the mounds are broadly self-similar in many respects, and interpret them as the original building blocks of Arrokoth. Determining whether a characteristic planetesimal building-block size can emerge from Streaming Instability (SI) simulations requires both new simulations at greater resolution than previously undertaken, and a thorough exploration of formation parameter space; regarding that much needed work, we present some promising early modeling results.
  30. Benecchi, S., Parker, A., Porter, S., et al., (including Grundy, W.), 2023, DPS, 55, 202.03, Colors of Cold Classical KBOs from the HST Solar System Origins Legacy Survey (SSOLOS)
    The dynamically distinct Cold Classical (CC) Kuiper Belt is a reservoir of small bodies that both observations and modeling identify as an in-situ primordial population. During HST Cycle 26 a legacy survey was executed to collect F606W and F814W filter photometry on a sample of 197 of these CCs (Hr<8) based on their discovery in the carefully designed and fully calibrated Outer Solar System Survey. The images were analyzed for binarity and measured photometrically using a Tiny Tim matching algorithm. We report on the final color results of this survey which found 25 of 197 objects to be well resolved (0.05") binaries yielding a binary fraction at face value of 13%; including partially resolved objects the fraction is closer to 20%. For resolved binaries there is a concentration of components with similar color consistent with previous studies, but no longer a perfect correlation. The binary systems are, on average, one magnitude brighter then solitary objects, but the blended binaries span the magnitude space between the two populations suggesting a continuum of sorts from bright to faint. We interpret that whatever is going on with color vs. size is really about size at formation, and not due to fragments of collisions being redder because we see that smaller objects appear redder in both the solitary and binary color results. Observations of Arrokoth's lobes by New Horizons also support this conclusion that binary components are related to formation mechanism and environment, not due to shattering by collisions. Support for this program was provided by NASA through a grant from STScI, which is operated by the AURA, Inc., under NASA contract NAS 5-26555.
  31. Fernandez-Valenzuela, E., Holler, B., Ortiz, J., et al., (including Levine, S., Collins, M., Zigo, H.), 2023, DPS, 55, 202.04, Weywot: the darkest known satellite in the trans-Neptunian region
    Several stellar occultations by Weywot, the only known satellite of the TNO Quaoar, were predicted to happen during May/June 2023. Weywot had been previously detected, although fortuitously, through stellar occultations with one chord from Namibia (Kretlow, 2019) and two chords from the US (although no data from that event have yet been published). Even with the two previous events, observations of the first two stellar occultations predicted to happen in May 2023 were unsuccessful. This required us to obtain new HST data in order to update the predicted path with the focus on the last stellar occultation that was crossing the continental US. HST data and a third successful, single-chord stellar occultation detected from New Zeland on May 26 helped us to confirm the predicted path and on June 22, 2023 at 07:52 UT, Weywot occulted the Gaia DR3 star 4103952409464066176 (V = 15.8 mag). We obtained four positive chords and several negative chords south of the body. Our preliminary results indicate that Weywot is a large satellite, with effective diameter at almost 200 km, which is consistent with the single-chord from Kretlow (2019). This is much larger than the estimated measurements from Herschel data, which indicated a diameter of ~80 km (Fornasier et al., 2013). Our new, larger estimate of Weywot's diameter requires a visual geometric albedo of ~4%, considering that it is 5 mag fainter than Quaoar (Fraser & Brown, 2013). Quaoar's albedo, on the other hand, is about three times larger (12.4 0.6%, Pereira et al., 2023). Weywot has turned out to be even more interesting than previously thought. While most TNO satellites have circularized orbits, Weywot's orbital eccentricity, e, is somewhere between 0 and 0.1 (Vachier's private communication). If the satellite was formed through a giant impact during the massive disk phase in which collisional activity was very intense (Morbidelli and Nesvorny, 2020), then the satellite's orbit should have been circularized through tidal evolution (as is the case for Dysnomia, Eris' satellite, and Hi'iaka, Haumea's largest satellite) with e ~ 0. The circularization timescale for an object formed via giant impact is only a few million years (Brunini, 2020) but should be longer for an object that was captured, since it would initially be on an orbit with a larger semi-major axis. Also, the large difference in the albedo between Weywot and Quaoar supports the possibility of Weywot being a captured satellite. However, an effective diameter of almost 200 km places its size in a similar range to those of other dwarf planets satellites, which are believed to have very different formation scenarios.
  32. Thirouin, A., Grundy, W., Sheppard, S., et al., 2023, DPS, 55, 202.05, Mutual events in the trans-Neptunian belt
    Unlike binary systems in the inner Solar System, the trans-Neptunian binaries have a wide range of characteristics, from a large primary with a small moon to (near) equal-sized binaries with primary and secondary having similar sizes, and from close/contact binaries if the distance between the components is small/inexistent to ultra-wide binaries with a very large distance between the components. A powerful technique to learn about binary systems is the observation of mutual events between the system's components. A mutual event happens when the secondary is passing in front or behind the primary. This technique has been utilized for decades to characterize binary main-belt asteroids, near-Earth objects, and Jupiter's Trojans to improve the satellite's orbit computation and the estimations of the size, shape, density, and albedo for each component. However, successful events have been detected in the trans-Neptunian belt for only two systems: Pluto-Charon and Sila-Nunam. We have identified 10 additional trans-Neptunian binaries which are undergoing/will undergo mutual events seasons. In order to successfully predict and observe mutual events, we obtained some ground-based lightcurves for most of these systems over the past few years. Lightcurves will be used to extract some basic characteristics of the systems, such as rotational period, and constraints for the shapes. These characteristics will then be used as inputs for lightcurve modeling to predict as accurately as possible the mutual events seasons and the individual mutual events. Ultimately, our lightcurve modeling will be put to the test by observing some mutual events.
  33. Hanley, J., Thieberger, C., Corlies, P., et al., (including Llama, J.), 2023, DPS, 55, 208.02, Constraining the Variability of Haze and Methane on Titan
    Titan hosts a thick atmosphere with complex organic chemistry resulting from the UV photolysis of methane, forming complex aerosols that obscure Titan's surface. Further, methane acts as the primary absorber in the near-IR, resulting in narrow "windows" that probe to intermediate depths of Titan's atmosphere allowing vertical retrievals of methane and haze abundance. We will present observations from the Lowell Discovery Telescope (LDT) centered across various longitudes in order to get an integrated global picture of these vertical distributions and to look for global scale and temporal differences in these distributions. These observations provide critical insights into the chemical pathways in the upper atmosphere and help constrain the rate of UV photolysis, and by extension the loss-rate of methane, which remains an open question in the Titan community. We use LDT's EXtreme PREcision Spectrometer (EXPRES) observations to study the spectral features of Titan visible spectrum from ~0.4 - 0.75 m at a resolution of R ~ 137,500. This slope is set by absorption of UV and visible light by aerosols, and will lead to constraints on the composition and vertical abundance of hazes in Titan's atmosphere, similar to the photometric analysis conducted with HST. In addition, measuring the shape and strength of the methane absorption feature at 0.62 m at high resolution will allow for sensitive constraints on the vertical distribution of methane in Titan's atmosphere, similar to studies conducted with Keck. To complement the visible wavelengths, we also observe with LDT's Near-Infrared High-Throughput Spectrograph (NIHTS) which is a low-resolution (R ~ 200) near-infrared (NIR) prism spectrograph, covering 0.86 - 2.4 m. NIHTS provides access to the five methane windows (at 0.938, 1.1, 1.3, 1.6, and 2.0 m) that can see down to Titan's surface, permitting us to complete the vertical abundance retrievals through Titan's entire atmosphere. Data from EXPRES shows many features attributed to reflected sunlight, but also the larger methane features expected at ~0.62 and 0.7 m. The high resolution will allow for broad features such as UV absorption of hazes, as well as narrow features attributed to specific molecules yet to be determined. Preliminary analysis of NIHTS data shows good signal-to-noise that will allow for correlation with the EXPRES data and will permit studies of the longitudinal variability in Titan's methane abundance.
  34. Porter, S., Singer, K., Schenk, P., et al., (including Grundy, W.), 2023, DPS, 55, 209.01, Constraints on the Formation of Classical KBOs from the Shape of Arrokoth
    The cold classical KBO (486958) Arrokoth is the only classical KBO to have been visited by a spacecraft, NASA's New Horizons in January 2019. Arrokoth is formed from two separate lobes, the larger lenticular lobe "Wenu" and a smaller, more spherical lobe "Weeyo". The very narrow contact point between the lobes implies that they were fully formed separately and later merged to form the final contact binary. This formation story is consistent with their rapid formation by the Streaming Instability (SI) from the same cloud of material and later slow, non-violent contact. In this work, we use the newly updated and improved shape mode of Arrokoth to explore how the shapes of Wenu and Weeyo constrain both the formation of Arrokoth, and of other, similar KBOs. This is particularly important given the binary and contact-binary rates are comparably high in the Kuiper Belt, and the true rate of contact binaries could be much higher than photometric surveys suggest. We look how well the lobes are aligned to each other, a critical test of the speed of their contact. We explore the apparent hexagonal shape of Wenu, which constrains its formation. We also address separated binary classical KBOs, which are likely to have similar shapes to the lobes of Arrokoth, and how the large J2 of an object like Wenu can modify the orbital evolution of a binary KBO.
  35. Sciamma-O'Brien, E., Bertrand, T., Brubach, J., et al., (including Grundy, W.), 2023, DPS, 55, 220.01, New Optical Constants of Titan and Pluto Aerosol Analogs from the Visible to the Infrared and Their Use to Analyze Cassini and New Horizons Observations
    In planetary atmospheres like those of Titan and Pluto, complex organic solid particles are produced from photolysis and radiolysis processes. These aerosols form haze layers, and also settle to the surface. Their presence can significantly impact the atmospheric and surface spectra obtained by remote-sensing instruments like the Visible Infrared Mapping Spectrometer and Composite Infrared Spectrometer on Cassini and the Ralph instrument on New Horizons. Numerous laboratory experiments have been developed to simulate and investigate the chemistry occurring in Titan's and more recently Pluto's atmosphere, resulting in the formation of these solid particles. Many different analytical diagnostics have been used to characterize laboratory-generated analogs (or tholins) of Titan and Pluto aerosols and provide insight on their formation pathways and physical, chemical, and spectral properties. In particular, the complex refractive indices (n + ik, or optical constants) of a variety of Titan and Pluto tholins have been measured over the years. These optical constants describe how the tholins interact with light (transmission, reflection, absorption, scattering), and are therefore fundamental input parameters to simulate haze particles in radiative transfer models used for the interpretation of observational data. These radiative transfer models can leverage the optical constants of different tholins to explore a wide range of compositions, allowing for improved fits and interpretations of observational data resulting in a better understanding of Titan's and Pluto's atmosphere and surface compositions. Here we present the results of several optical constants studies: 1. The measurements of optical constants of Titan tholins produced from plasma chemistry in N2:CH4-based gas mixtures in the NASA Ames COSmIC Facility from the Visible to the Near Infrared (0.41.6 m) and their use in a new analysis of Cassini VIMS observations[1]. 2. The measurements of optical constants of Pluto tholins produced in N2:CH4:CO gas mixtures in COSmIC from 0.4 to 1.6 m and their use in a new analysis of New Horizons Ralph observations[2,3]. 3. The preliminary results of a comparative analysis of two Titan tholin samples produced from plasma chemistry in N2:CH4 gas mixtures in two different experimental facilities: the LATMOS PAMPRE experiment and the NASA Ames COSmIC facility, and measured from 0.4 to 300 m[4]. References: [1] Sciamma-O'Brien, E., et al. 2023; PSJ (in press). [2] Emran, A., et al. (2023) 54th LPSC. [3] Cook, J. C., et al. (2023) 54th LPSC. [4] Drant, T., et al. 2023; A&A (submitted).
  36. Glein, C., Grundy, W., Protopapa, S., et al., 2023, DPS, 55, 301.01, Deuterium decoded: How the D/H ratio can clarify the origin of methane in the Kuiper belt
    Methane is abundant on several large icy worlds. This makes the origin of methane an important issue in the outer solar system. So far, though, almost all of the attention on this topic has been focused on Titan, and we still lack a comprehensive framework to determine the origin of methane. Moreover, opportunities are emerging on more distant bodies, which are now being characterized in stunning detail by the James Webb Space Telescope (JWST). We are thus motivated to develop new geochemical models for the origin of methane on solid bodies in the outer solar system. Here, we describe a framework to constrain the origin of methane based on its D/H ratio. We consider three types of methane that may exist on icy worlds: primordial, abiotically synthesized, and thermogenic. From a detailed review, we were able to set limits on the D/H ratio for each type of methane using data from comet 67P, Earth hydrothermal systems, and carbonaceous chondrites. We have also considered how escape and photochemical processes could have led to deuterium enrichment at the surfaces of icy worlds. We find that primordial methane should be isotopically distinct from abiotic and thermogenic methane in the outer solar system. Primordial methane is expected to have a high D/H ratio (>510-4). Abiotic methane should have a lower D/H than thermogenic methane. Hydrogen atoms in abiotic methane would be derived from water, while thermogenic methane could acquire its hydrogen atoms from both organic matter and water. Using our geochemical models, we can predict the D/H ranges for different origin-of-methane scenarios on Kuiper Belt Objects. We will present our predictions and show how they can be used to interpret JWST data from Eris and Makemake, providing our first isotopic clues to the formation conditions and interior evolution of these enigmatic worlds.
  37. Protopapa, S., Stansberry, J., Wong, I., et al., (including Grundy, W.), 2023, DPS, 55, 301.02, Unveiling new species on the stratified surface of Charon through JWST
    Charon, Pluto's largest moon, has been the focus of extensive spectral analysis through both terrestrial observations and data collected by the New Horizons mission. These investigations have uncovered a surface dominated by crystalline water ice and ammoniabearing species, which appear enhanced in the bright ejecta blankets of geologically young craters, suggesting the exposure of subsurface materials. Given the limited spectral coverage of Charon's measurements to date (up to 2.5 m), some aspects of Charon's composition remain unresolved, including 1) the detection of carbon dioxide (CO2) on the surface of Charon, expected to be present in regions revealing exposure to subsurface materials, but never detected so far, and 2) the role of energetic radiation and UV photolysis on water ice, ammoniated species, and C-bearing species. We present JWST observations of Charon acquired as part of the Solar System Guaranteed-Time-Observations (GTO) program # 1191 (PI: Stansberry), using the Near-Infrared Spectrograph (NIRSpec) instrument on JWST. These observations longitudinally encompass the entire surface of Charon. Observations were obtained with three high-resolution gratings (G140H, G235H, G395H) and two detectors per grating (nrs1, nrs2) resulting in a spectral coverage between 1.1 and 5.1 m with an average resolving power of R ~ 2700. These observations confirm previously identified absorption bands at 1.5, 1.65 and 2.0 m due to crystalline water ice and a ~2.2 m feature attributed to ammoniated species. Beyond 2.5 m, the spectrum is dominated by prominent H2O ice features at 3.0 m, 3.1 m (Fresnel peak), and 4.5 m. The spectrum clearly displays a sharp feature at 2.7 m and two absorptions centered around ~4.24 m and ~4.27 m. We attribute these features to CO2, byproducts created by irradiation damage of CO2-rich material, or a combination of the two. Additionally, absorption features resulting from hydrogen peroxide (H2O2) are seen in the spectra, possibly resulting from water-ice radiolysis. Considering the established connections between Charon and various celestial bodies, including Kuiper Belt objects, icy satellites and comets, these results offer insights into potentially common elements that may exist within the regions of the solar nebula from which these bodies originated and the possibility of shared radiolytic and/or photolytic by-products. Acknowledgments: This work is based on observations made with the NASA/ESA/CSA James Webb Space Telescope. S.P. thanks the NASA grants 80NSSC19K0821 and 80NSSC19K0554 to SwRI for partial funding that supported her work.
  38. Pinilla-Alonso, N., Stansberry, J., Holler, B., et al., (including Grundy, W.), 2023, DPS, 55, 301.04, Detection of ice and gas species on Pluto spectra with James Webb Space Telescope
    In this work, we present the analysis and discussion of the first 0.6-5.2 m spectra of Pluto at four different longitudes obtained with the James Webb Space Telescope (JWST). These spectra were acquired during year 1 of operations of JWST under the GTO-1 program #1191, led by J. Stansberry. The high-resolution (R~2700), high-sensitivity combination of Webb/NIRSPEC using G140H, G235H, and G395H enables the robust detection of a diverse set of solid species. Some of these species, CH4, -N2, CO and and C2H6 were previously known or suggested while others are now detected for the first time, including CH3D (deuterated methane) and CO2. The spectra also show expected absorptions by CH4 gas from Pluto's atmosphere, and for the first time, fluorescent emissions due to CH4, CO and CH3D gas at 3.3, 4.7 and 4.54 m respectively
  39. Emery, J., Cook, J., Pinilla-Alonso, N., et al., (including Grundy, W.), 2023, DPS, 55, 301.08, JWST/NIRSpec Spectrum of the Inner Oort Cloud Dwarf Planet (90377) Sedna
    The dwarf planet (90377) Sedna is the largest of the three known members of the Inner Oort Cloud (IOC) population. Ground-based visible and near-infrared (NIR; 0.4 to 2.5 m) spectra of Sedna showed absorption near 2.3 m previously ascribed to CH4 and/or CH3OH ice, hints of H2O ice and a steep red spectral slope suggestive of complex organics. Photometry at 3.6 and 4.5 m measured with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope indicated strong absorption bands relative to the 2-m region and support spectral models that include H2O ice and simple hydrocarbons. However, the low S/N of the NIR spectra and photometric nature of the IRAC data hinder detailed compositional analysis. With equilibrium temperatures of ~30 K and ~9 K at perihelion (~76AU) and aphelion (~937 AU), respectively, a wide range of ices should be stable on the surface. Sedna was observed by the James Webb Space Telescope (JWST) using the NIRSpec IFU in prism mode. The observations were part of GTO program 1272 (PI D. Hines) and occurred on Sept 13, 2022 (17:18-17:49 UT). The spectrum covers the wavelength range 0.75.3 m with a spectral resolving power of ~100. H2O ice bands suggested in the ground-based spectra at 1.5 and 2.0 m are confirmed, and distortions of the band shapes indicate significant contamination of the ice by other materials. The absorption band complex near 2.3 m is revealed with significant substructure. At > 2.5 m, the overall level of reflectance is consistent with the Spitzer/IRAC photometry. A broad and deep absorption from ~2.8 to 3.5 m is likely due to H2O ice, as is a gentle curvature at ~45 m. Several narrower absorption bands throughout the NIRSpec prism wavelength range are consistent with ethane (C2H6) ice, including a very strong absorption complex near 3.4 m. Interestingly, the strong absorption from methane (CH4) at 3.3 m is not apparent in the spectrum, nor does CH3OH appear to be present. We will present the JWST spectrum of Sedna in the context of the previous ground-based and Spitzer data and will present new spectral analyses. Eventually, comparison of the composition of Sedna to other dynamical classes of Trans-Neptunian Objects (TNOs) will address the context of IOC objects within the TNO population.
  40. Sickafoose, A., Person, M., Zuluaga, C., et al., (including Bosh, A., Levine, S.), 2023, DPS, 55, 308.02, Pluto's Atmosphere Persists
    Pluto has a tenuous atmosphere with microbar-level surface pressure, composed primarily of nitrogen and containing a layered haze made of organic materials. An eccentric orbit combined with high obliquity leads to significant changes in solar insolation at different latitudes throughout the Plutonian year. Because the atmosphere is supported through vapor-pressure equilibrium with the surface ices, changes in surface conditions are intimately linked with the properties of the atmosphere. Thermophysical, volatile-transport models have been employed to anticipate Pluto's atmospheric evolution: predictions include atmospheric contraction or even collapse over the coming decades as well as an atmosphere that remains through the entire 248-yr revolution around the Sun (e.g. Young, 2013, ApJ Lett., 766, L22; Hansen et al. 2015, Icarus, 246, 183; Bertrand et al. 2018, Icarus, 309, 277; Johnson et al. 2021, Icarus, 356, id.114070). Previous work reported that Pluto's atmospheric pressure has been monotonically increasing since its definitive discovery in 1988 through 2016 (Meza et al. 2019, A&A, 625, id.A136) and then that the atmosphere had possibly begun freezing out in 2018-2019 (Arimatsu et al. 2020, A&A 638, L5; Young et al. 2021, AAS DPS Meeting #53, id.307.06). Observations of an occultation in 2020 did not show a pressure drop and were interpreted to be either a continued pressure increase (Poro et al. 2021, A&A, 652, L7) or a plateau phase (Sicardy et al. 2021, ApJ Lett, 923, L31). Here, we report results from nine successfully-observed stellar occultations by Pluto between 2017 August and 2022 August. The stellar magnitudes ranged from G=12.91 to 17.76 with geocentric relative velocities between 1.7 and 24.3 km/s. Four of these events had successful chords from multiple sites, while five events were from single sites. Our results indicate that Pluto's atmospheric pressure has been roughly holding steady since the New Horizons spacecraft flyby in 2015 and does not show any signs of collapse as of August 2022.
  41. Raposa, S., Grundy, W., Tan, S., et al., (including Hanley, J.), 2023, DPS, 55, 308.07, Phase Diagram Mapping of the N2+CH4+CO System to Better Understand Pluto's Glaciers
    N2, CH4 and CO are highly abundant volatiles at places such as Pluto, Triton, Eris and Makemake. Pluto's Sputnik Planitia, for example, is a giant glacial reservoir of this ternary mixture. It is mobile species, like these three, that shape the geology of a body, making it important to study how they interact with one another. However, there are gaps in the literature of fully mapped phase diagrams for these materials, which limits our knowledge of these interactions. This affects models of outer solar system bodies because they must assume a simpler compositional makeup for a given region of interest. For instance, Sputnik Planitia is often assumed to be pure N2, even though the addition of CH4 and CO affects glacial behaviors, such as what phases are present under different surface conditions. This work aims to address these unknowns by using laboratory methods and thermodynamic modeling to create an accurate equation of state (EOS) for the ternary system. This EOS will describe what phases are present for any temperature, pressure, and composition point. In the Astrophysical Materials Laboratory at NAU, two laboratory methods are being implemented to map the three binary phase diagrams within the ternary system. The first method maps the three-phase solid-liquid-vapor curves of N2+CO, N2+CH4, and CO+CH4. This method is complete, and results are published (doi: 10.1063/5.0097465). The second method, which is underway, involves cooling a single composition, locating its phase boundaries using Raman spectroscopy, then later adjusting for supercooling. The phase boundary points are added to plots of temperature vs. composition for each binary system. This method is nearly complete for N2+CO, which will update the current curves in the literature, which are rough estimates, and do not account for supercooling. Work has also begun with the N2+CH4 system, which will be crucial to validate, since many models rely on the phase diagram derived from X-ray diffraction (Prokhvatilov & Yantsevich, 1983). Finally, the CO+CH4 temperature-composition phase diagram will be experimentally mapped for the first time. The laboratory results will fine-tune a thermodynamic model, CRYOCHEM, to create the EOS. CRYOCHEM is based on the Thermodynamic Perturbation Theory and couples the Perturbed-Chain Statistical Associating Fluid Theory for the fluid component with the Lennard-Jones Weeks-Chandler-Andersen approach for the solid part. The derived EOS will provide compositions and densities of the equilibrium phases for use by the community in geophysical, global circulation, and sublimation-condensation evolution models.
  42. McAdam, M., Singer, K., Hanley, J., et al., 2023, DPS, 55, 312.10, DPS Professional Development Subcommittee
    This abstract summarizes the DPS Professional Development Subcommittee. Please see our websites for more information: https://dps.aas.org/development. The purpose of the Professional Development Subcommittee is to have a group with formal standing within the DPS community and a broad base to identify and respond to the unique needs of our community. Our goals are to: Determine the professional development needs unique to our community. Provide educational experience for the membership. Encourage networking within the community. Build and maintain an information resource center. Strive for an inclusive community. The Professional Development Subcommittee typically hosts several events for the annual DPS meeting. These include the Student and Early Career Reception, a professional development workshop, and the Women in Planetary Science Discussion Hour. We also facilitate awards from the Susan Niebur Professional Development Fund. These are generally small grants for individuals to offset the cost of care (e.g., child care or elder care) for use either at the DPS meeting location or at home. Dependent care expenses needed to allow participation in DPS Annual Meetings in any format (virtual or in-person) are allowed. You may apply to this grant at https://dps.aas.org/development/dps-dependent-care-grant-application. The first deadline is August 7th, 2023 but we consider applications after this deadline if there are funds available. The Professional Development Subcommittee is soliciting new members and a new vice-chair. Current members can be found at https://dps.aas.org/leadership/development. Please reach out to the current chair or any of our membership to learn more!
  43. Athanasopoulos, D., Hanus, J., Avdellidou, C., et al., (including van Belle, G.), 2023, DPS, 55, 321.06D, Ancient Asteroids: An observing campaign reveals the spin states of asteroids that belong to the most ancient collisional families of our Solar System
    The first moments of our Solar System are determined by the gas phase of the protoplanetary disk, where the first solid bodies, the planetesimals, were formed. While planetesimals accreted to form planets, a lot of them were also removed during the violent phases of dynamical interaction with the growing planets, planetary migration and instability. However, few leftover planetesimals are still present today in the solar system as dwarf planets or even smaller bodies. Those of the inner Solar System formed an asteroid main belt. Reconstructing the original state of main belt is thus a crucial problem of planetary science to study the formation of the planets. The main belt collisions disrupted several of those original planetesimals creating new asteroids that initially stayed relatively close to the parent body, creating the so-called asteroid collisional families. But members of families disperse over time due to the Yarkovsky effect and interaction with orbital resonances. Traditional identification methods are unable to effectively recognize Gyr- and older asteroid families, which family members are very dispersed. A novel technique takes the advantage of the correlation between semimajor axis and size imprinted on family members by the Yarkovsky effect to identify the most ancient collisional families of the Solar System. The method has already successfully identified three primordial families which likely formed before the giant planet orbital instability and could be as old as the Solar System and an ancient one that is ~3 Gyr-old. There is evidence from observations and theoretical evolution models that there could be more old families than the ones currently detected. Here we report on the assessment of the reliability of these families by means of data independent of those used for the family detection: namely, we used the direction of the spin state of families' members. These data have been collected by the international observing campaign "Ancient Asteroids" involving both professionals and amateur astronomers. During the last 3 years, photometric observations of more than 120 asteroids were performed. The obtained lightcurves were combined with dense photometric data available in the literature, as well as with sparse data from space missions and global sky surveys. The results of this research confirm the existence of a 4 Gry-old low-albedo collisional family in the inner Main-Belt and uses the spin states as a crucial physical parameter for the reassessment of the members that belong to Athor and Zita families, which members are overlapping with similar spectral and albedo characteristics.
  44. Person, M., Sickafoose, A., Levine, S., et al., (including Bosh, A.), 2023, DPS, 55, 323.06, Triton's Changing Atmosphere
    Throughout the entire period Triton's atmosphere has been measured, from Voyager 2 in 1989 through the most recent stellar occultation measurements, Triton has been in a southern summer orientation. Its pole position has slowly evolved from a maximum sub-solar latitude of approximately 50 in the late 1990's through to 35 today, as it moves towards the summer-ending Triton equinox in the late 2040's (Park et al. 2021 AJ 161). Given the decades-long southern summer, one might expect the constant insolation of the southern hemispheric ice formations to result in increasing atmospheric pressure during this period. In fact, rapid growth was observed during the peak portion of the southern summer as occultation observations from 1995 through 2001 showed atmospheric pressure increasing two-fold in just those seven years. (Elliot et al. 1998 Nature 393; Person et al. 2001 BAAS 33) This trend was seen to suddenly reverse in 2017, with an occultation showing the pressure retreating towards its earlier levels, losing about half of the previously observed increases. (Person et al. 2018 DPS 50; this work) Unfortunately, the lack of suitable candidates prevented significant Triton observations in the period between 2002 and 2017, with only a few detections of low signal-to-noise ratio over those 15 years. That the observed rapid growth of the late 1990's has not only slowed with the ebbing summer, but apparently reversed in the course of just a few years indicates that Triton's atmospheric response to insolation is much less straight forward than simple polar cap warming models might suggest. Differences in thermal inertia between ice layers and different material transport models may help to explain some of this reaction (Hansen and Paige 1992 Icarus 99; Spencer and Moore 1992 Icarus 99; Bertrand et al., 2019 DPS 51, etc.), but as yet the sudden reversal remains unconstrained by modelling efforts. Here we present the analysis of the October 2022 Triton occultation of a 11.5 Gaia G magnitude star, which was extensively observed throughout Asia and environs by numerous groups. We present this reduction along with a re-reduction of prior occultation events with the same software and models in an attempt to verify the puzzling trends in Triton's atmosphere and provide a reliable and consistent atmospheric baseline for the development of newer models.
  45. Wong, I., Hines, D., Brunetto, R., et al., (including Grundy, W.), 2023, DPS, 55, 401.08, The complex surface and atmospheric properties of Triton revealed by JWST/NIRSpec
    The Kuiper belt holds the key to understanding the primordial environment within the outermost reaches of the protoplanetary disk. For decades, only the largest members of this population the dwarf planets were amenable to detailed characterization. While recent advances in telescope capabilities have widened the purview of spectroscopic exploration in the Kuiper belt, the dwarf planets continue to serve as important beacons for our investigations of the outer Solar System. Triton is an irregular satellite of Neptune that was captured from the Kuiper belt. With a diameter of 2710 km, it is the largest Trans-Neptunian Object (TNO) and one of only three large TNOs that have been visited by spacecraft. The 1989 Voyager 2 flyby revealed a highly inhomogeneous surface, evidence for cryovolcanism, and a tenuous nitrogen-dominated atmosphere, indicating complex surface processes and a complicated evolutionary history. Subsequent observations have produced detections of many ice species (CH4, CO2, CO, N2, H2O) and evidence for time-varying behavior in Triton's atmosphere. In this talk, we present new near-infrared spectra of Triton that were collected as part of Guaranteed Time Observations during the first year of JWST science operations (PID 1272; PI: Dean Hines). Triton was observed twice with the NIRSpec instrument using the high-resolution gratings, yielding exquisite spectra of the trailing and leading hemispheres spanning 0.9-5.3 m at a spectral resolving power of R~2700. The spectra are rich in ice absorption features across the full wavelength range. The detected feature set of CO2 ice is particularly extensive, with at least a dozen overtone and combination bands present. In addition, we report several isotopologue species, including CH3D, 13CO2, 12C18O2, and 13CO, from which we estimate the D/H, 13C/12C, and 18O/16O isotope ratios. Lastly, we have uncovered emission bands from atmospheric CO fluorescence at 4.7-4.9 m. We describe detailed compositional modeling of the surface and atmosphere, place the JWST spectra in the context of previous telescope observations, and discuss the implications for the formation and evolutionary history of Triton and the Kuiper belt at large.
  46. Thomas, C., DeMeo, F., Burt, B., et al., (including Moskovitz, N.), 2023, DPS, 55, 404.08, The MIT-Hawaii Near-Earth Object Spectroscopic Survey (MITHNEOS): Current Status and Future Plans
    Near-Earth objects (NEOs) represent an ongoing flux of small bodies from elsewhere in the Solar System to near-Earth space. The study of these objects teaches us about the original environment of the Solar System during formation and the conditions as physical and chemical changes occur throughout Solar System history. The MIT-Hawaii Near-Earth Object Spectroscopic Survey (MITHNEOS) began in 2004 and has obtained ~1,200 spectral observations of nearly 1,000 objects. The current phase of the project has three key goals: (1) to improve our understanding of the compositional distribution of NEO spectra with respect to asteroid size via additional IRTF SpeX prism spectra, (2) to examine the distribution of volatiles in the NEO population through an analysis of SpeX LXD 3-micron spectra, and (3) to transition the program from MIT and update our infrastructure (including the website). Our presentation will discuss the current status of MITHNEOS including our progress in the new 3-micron effort and the website transition. We will also discuss our upcoming work in these areas.
  47. Lisse, C., Steckloff, J., Prialnik, D., et al., (including Kareta, T.), 2023, DPS, 55, 408.06, 29P/Schwassmann-Wachmann: A Rosetta Stone for Amorphous Water Ice and CO2 -> CO Conversion in Centaurs and Comets?
    Centaur 29P/Schwassmann-Wachmann 1 is a highly active object orbiting in the transitional "Gateway" region between the Centaur and Jupiter Family Comet regions. SW1 is unique among the Centaurs, in that it experiences quasi-regular major outbursts and produces CO emission continuously; however, the source of the CO is unclear. We argue that due to its very large size (~32 km radius, Schambeau et al. 2015, 2020), Centaur SW1 is likely still responding, via amorphous water ice (AWI) conversion to crystalline water ice (CWI), to the "sudden" change in its external thermal environment produced by its dynamical migration from the Kuiper belt to the Gateway Region at the inner edge of the Centaur region at 6 au. It is this conversion process that we believe is the source of the abundant CO and dust released from SW1's nucleus during its quiescent and outburst phases. If correct, these arguments have a number of important, testable predictions (Lisse et al. 2022), including: the quick release on Myr timescales of CO from AWI conversion for any few km-scale scattered disk TNO transiting into the inner system; that to date SW1 has only converted between 50 to 65% of its nuclear AWI to CWI; that volume changes upon AWI conversion could have caused subsidence and cave-ins, but not significant mass wasting on SW1; that when SW1 transits into the inner system within the next ~1 Myr, it will be a very different kind of SP comet; and that SW1's coma should contain abundant amounts of CWI + CO2-rich "dust" particles that only slowly release their contents at large distances as they stream away from the nucleus.
  48. Chandler, C., Oldroyd, W., Trujillo, C., et al., (including Kueny, J.), 2023, DPS, 55, 411.05, Active Asteroid, Quasi-Hilda, and Jupiter Family Comet Discovery with Citizen Science
    Comets and asteroids, historically considered two separate populations, have become increasingly indistinguishable. One population that blurs the comet-asteroid boundary is the active asteroids, asteroids with features most often associated with comets, such as tails or comae. These objects provide insight into astrophysical processes (e.g., dynamical evolution), and help us map the past and present-day solar system volatile distribution. Asteroid activity is elusive, with only about 50 active asteroids identified among the 1.1 million known asteroids. An even smaller subset (roughly 20 objects) are the main-belt comets, asteroids experiencing sublimation-driven activity while orbiting within the main asteroid belt. To help find more active asteroids, thereby enabling the comprehensive study of these bodies as a population, we have embarked on a campaign to find more of these objects with the help of the public. We have created a Citizen Science project, Active Asteroids (http://activeasteroids.net), where we show volunteers images of known minor planets that we have produced from publicly available Dark Energy Camera data and ask them if they see activity or not. Launched on the Zooniverse online Citizen Science platform in August 2021, our NASA Partner program has received help from over 8,000 participants to carry out over 6 million classifications. Here we present the Active Asteroids program along with new results, including new active asteroids, quasi-Hilda objects, and Jupiter Family Comets, as well as updated statistics about these populations, such as their occurrence rates. This material is based upon work supported by the NSF Graduate Research Fellowship Program under grant No. 2018258765 and grant No. 2020303693. C.O.C., H.H.H., and C.A.T. acknowledge support from NASA grant 80NSSC19K0869. W.J.O. and C.A.T. acknowledge support from NASA grant 80NSSC21K0114. W.A.B. was supported in part by NSF award 1950901. This work is funded in part through the LSST Interdisciplinary Network for Collaboration for Computing (LINCC) Frameworks. LINCC Frameworks is supported by Schmidt Futures, a philanthropic initiative founded by Eric and Wendy Schmidt, as part of the Virtual Institute of Astrophysics (VIA).
  49. Chernyavskaya, M., Kramer, D., McNeill, A., et al., (including van Belle, G.), 2023, DPS, 55, 503.02, Asteroid Strengths From ZTF and the Solar system Notification Alert Processing Pipeline (SNAPS)
    The Solar System Notification Alert Processing System (SNAPS) [1] is a data processing pipeline and database that ingests asteroid observations from the Zwicky Transient Facility (ZTF). SNAPShot1 [1] presents measured and derived properties (lightcurve amplitude, rotation period, color, absolute magnitude, etc.) for ~30,000 asteroids. Using these properties, we have modeled the minimum strength required to withstand rotational fission for all SNAPS asteroids. We find that 456 asteroids require non-zero minimum strength, which represents the largest set of such values calculated to date. These 456 objects do not all fall under the canonical 2.2 hour spin barrier typically assigned to Super Fast Rotators. In fact, many of the 456 objects have rotational periods greater than 2.2 hours. These results show that the conversation should be shifted from a two-dimensional spin barrier to a three-dimensional strength boundary surface in the space defined by size, elongation, and period. Additionally, we find that the strength distributions for big asteroids and small asteroids differ, though the distributions for C/S and inner/outer belt are indistinguishable. We hypothesize that this divergence across size regimes is caused by the underlying size-strength correlation. Overall, larger objects tend to require higher additional strength than smaller objects. The smaller objects in the large object distribution end up not being able to withstand rotational fission and either shell off material or experience disruption to their strength. This results in a reduction in size, and they migrate into the small object distribution, or lose strength and are no longer a part of the populations we are studying. At DPS we will present all of these results and a discussion of future directions of investigation. This work is supported in part by the Arizona Board of Regents and NSF grant 2206796. Citations: [1] Trilling, D. E. et al. (2023) AJ, 165, 111.
  50. Bourdelle de Micas, J., Fornasier, S., Delbo, M., et al., (including van Belle, G.), 2023, DPS, 55, 503.07, Spectroscopic characterization of a primordial S-type family in the inner main belt
    A primordial family was discovered recently in the inner main belt. Its age was estimated to be 4.4 1.7 Gyr ago, during the early stages of the Solar System, asteroids started their formation. From a list of 265 asteroids potentially members of the family, we carried out spectroscopic observations, in visible and NIR range, that includes ground-based observations, data from literature and the use of the recent release of Gaia (DR3). In total, we obtained spectra of 263 asteroids out of 265. We performed taxonomical classification, following the Bus-DeMeo taxonomy, and we computed spectral parameters such as the spectral slope and the center and depth of absorption bands when resent in the spectra. To do so, we used the M4AST online tool, and we gathered information about albedo and size of the objects with the Minor Planet Physical Properties Catalog (MP3C). From the taxonomical distribution of the potential members, we established a method to identify interlopers, specially among the S- and X-complex, and V-types population. We identified that 68 asteroids are interlopers, reducing the list of PSTF members to 193 objects. We found that 70% of members belong to the S-complex. Spectral features studies reveal that these S-type members show a variety of silicate composition, ranging from S I to VII in the Gaffey classification scheme. Moreover, the biggest members of that family is the asteroid (30) Urania, with a diameter of around 91 km. In addition to the S-complex, we found that 15% of these members belong to the L-type and 9% to the V-type. In total, the mean albedo of that family is estimated to be 22.5 2.7%. With the comparison with another S-complex family of the inner main belt, Flora, we found a taxonomical distribution similar to the one of the PSTF. Through the size distribution of the PSTF, we estimated the size of its parent body to be between 140 and 230 km. This size range is compatible with a progenitor of H or L chondrites. This family could be the source of some S-complex NEOs, such as asteroid (98943) 2001 CC21, the fly-by target of the extended Hayabusa2 mission. Acknowledgements: We acknowledge support from the ANR-ORIGINS (ANR-18-CE31-13-0014). This work made use of observations collected at the Copernico telescope (Asiago, Italy) of the Istituto Nazionale di Astrofisica (INAF), at the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma, Spain, and at the Lowell Discovery Telescope at Lowell Observatory. We acknowledge financial support from ASI contract No. 2022-12-HH.0. This work has made use of data from the European Space Agency (ESA) mission Gaia.
  51. Kareta, T., Vida, D., Brown, P., et al., (including Moskovitz, N.), 2023, DPS, 55, 510.02, Telescope-to-Fireball Characterization of Earth Impactor 2022 WJ1
    The sixth-discovered Earth Impactor, 2022 WJ1, was a meter-scale near-Earth asteroid found only hours before it contacted the upper atmosphere over the Great Lakes in November of 2022. In this presentation, we will describe our international observational campaign to understand WJ1 as an asteroid in space (through photometric observations with the 4.3 m Lowell Discovery Telescope) and how it broke up in the atmosphere (through video observations with a network of ground-based meteor camera stations). Connecting asteroidal observations to fireball data provides ways to debias both datasets, from a clearer understanding of what kinds of meteorites might be on the ground to the mechanical properties of the smallest asteroids that are usually inaccessible to remote sensing techniques. Both sets of analyses appear to be in broad agreement the fragmentation profile of the fireball, its photometric mass, and the asteroid photometric colors indicate an object with a stony composition, likely analogous to the ordinary chondrites. This implies a moderate albedo (~25%) for the asteroid, and thus makes 2022 WJ1 the smallest designated asteroid meaningfully characterized in space less than half a meter in diameter. The in-space and fireball-derived pre-impact orbits for the object are statistically identical, and while much of the smaller 1 - 100 g meteorites are likely underwater in Lake Ontario, the main ~20 kg fragment landed on the ground and is yet to be found. This was the first time an object was detected in space and so thoroughly characterized by ground-based facilities so thoroughly (now followed by a second event in France, 2023 CX1). This kind of event will become much more common thanks to upcoming surveys. We will present and elaborate on these results as well as constraints on the rotation rate of WJ1 prior to contact with the atmosphere, refinement of the fragmentation modeling and relative movement of the individual fragments, as well as lessons learned on how best to characterize these rare events.
  52. Rommel, F., Braga-Ribas, F., Ortiz, J., et al., (including Collins, M.), 2023, A&A, 678, A167, A large topographic feature on the surface of the trans-Neptunian object (307261) 2002 MS4 measured from stellar occultations
    Context. The physical characterization of trans-Neptunian objects is essential for improving our understanding of the formation and evolution of our Solar System. Stellar occultation is a ground-based technique that can be successfully used to determine some of the TNOs' fundamental physical properties with high precision, such as size and shape.
    Aims: This work is aimed at constraining the size, shape, and geometric albedo of the dwarf planet candidate (307261) 2002 MS4 through the analysis of nine stellar occultation events. Using multichord detection, we also study the object's topography by analyzing the obtained limb and residuals between the observed chords and the best-fit ellipse. Metods. We predicted and organized the observational campaigns of nine stellar occultations by 2002 MS4 between 2019 and 2022, resulting in two single-chord events, four double-chord detections, and three events with between 3 and 61 positive chords. We derived the occultation light curves using differential aperture photometry, from which the star ingress and egress instants were calculated. Using 13 selected chords from the 8 August 2020 event, we determined the global elliptical limb of 2002 MS4. The best-fit ellipse, combined with the object's rotational information from the literature, sets constraints on the object's size, shape, and albedo. Additionally, we developed a new method to characterize the topography features on the object's limb.
    Results: The global limb has a semi-major axis of a = 412 10 km, a semi-minor axis of b= 385 17 km, and the position angle of the minor axis is 121 16. From this instantaneous limb, we obtained 2002 MS4's geometric albedo of pV = 0.1 0.025, using HV = 3.63 0.05 mag and a projected area-equivalent diameter of 796 24 km. Significant deviations from the fitted ellipse in the northernmost limb were detected from multiple sites, highlighting three distinct topographic features: one 11 km depth depression, followed by a 255+4 km height elevation next to a crater-like depression, with an extension of 322 39 km and 45.1 1.5 km deep.
    Conclusions: Our results indicate the presence of an object that is 138 km smaller in diameter than that derived from thermal data, possibly indicating the presence of a thus-far unknown satellite. However, within the error bars, the geometric albedo in the V-band is in agreement with the results published in the literature, even with the radiometric-derived albedo. This stellar occultation has allowed for the first multichord measurement of a large topography in a TNO.

    Tables B.1-B.5 are available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr ( or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/678/A167

  53. Keller, C., 2023, SPD, 55, 405.03, Unleashing the power of physics-informed neural networks: time-dependent, 3-D radiative hydrodynamics models that reproduce movies of the solar photosphere
    Current, realistic numerical simulations of the solar atmosphere reproduce observations in a statistical sense; they do not exactly reproduce observations such as a movie of solar granulation. Physics-informed neural networks (PINNs) offer a new approach to solving the time-dependent radiative hydrodynamics equations that easily includes observations as boundary conditions. PINNs approximate the solution of the integro-differential equations with a deep neural network. The parameters of this network are determined by minimizing the residuals with respect to the physics equations and the observations. Ever increasing advances in machine learning make it now possible to tackle this massive optimization problem even on a laptop computer. The resulting PINN models are continuous in all dimensions, can zoom into local areas of interest in space and time, and provide information on physical parameters that are not necessarily observed such as horizontal velocities within granules. PINNs can also extrapolate in space and time beyond the directly observed domain, all while using only a small fraction of the storage space of classical numerical models. I will present the first results of this novel approach applied to synthetic observations of the solar photosphere, explain the underlying methodology and provide an outlook to applying the tool to actual solar observations and including additional physics such as magnetic fields. This is only the very first step in an exciting direction that has the potential to revolutionize the way we interpret solar observations, understand the underlying physics and approximate solar processes on small scales such that they can be efficiently included in simulations at much larger scales.
  54. Noll, K., Brown, M., Buie, M., et al., (including Grundy, W.), 2023, SSRv, 219, 59, Trojan Asteroid Satellites, Rings, and Activity
    The Lucy mission will encounter five Jupiter Trojans during its mission with three of the five already known to be multiple systems. These include a near-equal-mass binary, a small and widely separated satellite, and one intermediate-size satellite system. This chapter reviews the current state of knowledge of Trojan asteroid satellites in the context of similar satellite systems in other small body populations. The prospects for the detection of additional satellites as well as other near-body phenomena are considered. The scientific utility of satellites makes their observation with Lucy an important scientific priority for the mission.
  55. Zhao, L., Dumusque, X., Ford, E., et al., (including Llama, J.), 2023, AJ, 166, 173, The Extreme Stellar-signals Project. III. Combining Solar Data from HARPS, HARPS-N, EXPRES, and NEID
    We present an analysis of Sun-as-a-star observations from four different high-resolution, stabilized spectrographs-HARPS, HARPS-N, EXPRES, and NEID. With simultaneous observations of the Sun from four different instruments, we are able to gain insight into the radial velocity precision and accuracy delivered by each of these instruments and isolate instrumental systematics that differ from true astrophysical signals. With solar observations, we can completely characterize the expected Doppler shift contributed by orbiting Solar System bodies and remove them. This results in a data set with measured velocity variations that purely trace flows on the solar surface. Direct comparisons of the radial velocities measured by each instrument show remarkable agreement with residual intraday scatter of only 15-30 cm s-1. This shows that current ultra-stabilized instruments have broken through to a new level of measurement precision that reveals stellar variability with high fidelity and detail. We end by discussing how radial velocities from different instruments can be combined to provide powerful leverage for testing techniques to mitigate stellar signals.
  56. Hernandez-Lang, D., Klein, M., Mohr, J., et al., (including Kuehn, K.), 2023, MNRAS, 525, 24, The PSZ-MCMF catalogue of Planck clusters over the DES region
    We present the first systematic follow-up of Planck Sunyaev-Zeldovich effect (SZE) selected candidates down to signal-to-noise (S/N) of 3 over the 5000 deg2 covered by the Dark Energy Survey. Using the MCMF cluster confirmation algorithm, we identify optical counterparts, determine photometric redshifts, and richnesses and assign a parameter, fcont, that reflects the probability that each SZE-optical pairing represents a random superposition of physically unassociated systems rather than a real cluster. The new PSZ-MCMF cluster catalogue consists of 853 MCMF confirmed clusters and has a purity of 90 per cent. We present the properties of subsamples of the PSZ-MCMF catalogue that have purities ranging from 90 per cent to 97.5 per cent, depending on the adopted fcont threshold. Halo mass estimates M500, redshifts, richnesses, and optical centres are presented for all PSZ-MCMF clusters. The PSZ-MCMF catalogue adds 589 previously unknown Planck identified clusters over the DES footprint and provides redshifts for an additional 50 previously published Planck-selected clusters with S/N>4.5. Using the subsample with spectroscopic redshifts, we demonstrate excellent cluster photo-z performance with an RMS scatter in z/(1 + z) of 0.47 per cent. Our MCMF based analysis allows us to infer the contamination fraction of the initial S/N>3 Planck-selected candidate list, which is ~50 per cent. We present a method of estimating the completeness of the PSZ-MCMF cluster sample. In comparison to the previously published Planck cluster catalogues, this new S/N>3 MCMF confirmed cluster catalogue populates the lower mass regime at all redshifts and includes clusters up to z~1.3.
  57. McNeill, A., Gowanlock, M., Mommert, M., et al., (including Trilling, D., Llama, J.), 2023, AJ, 166, 152, An Untargeted Survey of the Rotational Properties of Main-belt Asteroids using the Transiting Exoplanet Survey Satellite (TESS)
    We present photometric data for minor planets observed by the Transiting Exoplanet Survey Satellite during its Cycle 1 operations. In total, we extracted usable detections for 37,965 objects. We present an examination of the reliability of the rotation period and light-curve amplitudes derived from each object based upon the number of detections and the normalized Lomb-Scargle power of our period fitting and compare and contrast our results with previous similar works. We show that for objects with 200 or more photometric detections and a derived normalized, generalized Lomb-Scargle power greater than 0.2, we have an 85% confidence in that period; this encompasses 3492 rotation periods we consider to be highly reliable. We independently examine a series of periods first reported by Pal et al.; periods derived in both works found to have similar results should be considered reliable. Additionally, we demonstrate the need to properly account for the true proportion of slow rotators (P > 100 hr) when inferring shape distributions from sparse photometry.
  58. Mosenkov, A., Rich, R., Fusco, M., et al., (including West, M.), 2023, MNRAS, 525, 3016, The haloes and environments of nearby galaxies (HERON) - III. A 45-kpc spiral structure in the GLSB galaxy UGC 4599
    We use a 0.7-m telescope in the framework of the Halos and Environments of Nearby Galaxies (HERON) survey to probe low surface brightness (LSB) structures in nearby galaxies. One of our targets, UGC 4599, is usually classified as an early-type galaxy surrounded by a blue ring making it a potential Hoag's Object analogue. Prior photometric studies of UGC 4599 were focused on its bright core and the blue ring. However, the HERON survey allows us to study its faint extended regions. With an 8-h integration, we detect an extremely faint outer disc with an extrapolated central surface brightness of 0, d(r) = 25.5 mag arcsec-2 down to 31 mag arcsec-2 and a scale length of 15 kpc. We identify two distinct spiral arms of pitch angle ~6 surrounding the ring. The spiral arms are detected out to ~45 kpc in radius and the faint disc continues to ~70 kpc. These features are also seen in the GALEX far- and near-ultraviolet bands, in a deep u-band image from the 4.3-m Lowell Discovery Telescope (which reveals inner spiral structure emerging from the core), and in H I. We compare this galaxy to ordinary spiral and elliptical galaxies, giant low surface brightness (GLSB) galaxies, and Hoag's Object itself using several standard galaxy scaling relations. We conclude that the pseudo-bulge and disc properties of UGC 4599 significantly differ from those of Hoag's Object and of normal galaxies, pointing toward a GLSB galaxy nature and filamentary accretion of gas to generate its outer disc.
  59. Barnes, J., Standing, M., Haswell, C., et al., (including Llama, J.), 2023, MNRAS, 524, 5196, DMPP-4: candidate sub-Neptune mass planets orbiting a naked-eye star
    We present radial velocity measurements of the very bright (V ~ 5.7) nearby F star, DMPP-4 (HD 184960). The anomalously low Ca II H&K emission suggests mass-loss from planets orbiting a low activity host star. Periodic radial velocity variability with ~10 m s-1 amplitude is found to persist over a >4 yr time-scale. Although the non-simultaneous photometric variability in four TESS sectors supports the view of an inactive star, we identify periodic photometric signals and also find spectroscopic evidence for stellar activity. We used a posterior sampling algorithm that includes the number of Keplerian signals, Np, as a free parameter to test and compare (1) purely Keplerian models (2) a Keplerian model with linear activity correlation and (3) Keplerian models with Gaussian processes. A preferred model, with one Keplerian and quasi-periodic Gaussian process indicates a planet with a period of $P_\textrm {b} = 3.4982^{+0.0015}_{-0.0027}$ d and corresponding minimum mass of $m_\textrm {b}\, \textrm {sin}\, i = 12.2^{+1.8}_{-1.9}$ M. Without further high-time resolution observations over a longer time-scale, we cannot definitively rule out the purely Keplerian model with two candidates planets with $P_\textrm {b} = 2.4570^{+0.0026}_{-0.0462}$ d, minimum mass $m_\textrm {b}\, \textrm {sin}\, i = 8.0^{+1.1}_{-1.5}$ M and $P_\textrm {c} = 5.4196^{+0.6766}_{-0.0030}$ d and corresponding minimum mass of $m_\textrm {b}\, \textrm {sin}\, i = 12.2^{+1.4}_{-1.6}$ M. The candidate planets lie in the region below the lower-envelope of the Neptune Desert. Continued mass-loss may originate from the highly irradiated planets or from an as yet undetected body in the system.
  60. Prochaska, J., Hennawi, J., Cooke, R., et al., (including Ellsworth Bowers, T.), 2023, zndo, pypeit/PypeIt: Version 1.14.0
    Dependency Changes Main dependency bumps: numpy>=1.22, matplotlib>=3.7, ginga>=4.1.1, qtpy>=2.0.1 Functionality/Performance Improvements and Additions Improvements to wavelength grids and masking in coadd routines. Refactored coadding routines to work with lists to support coadding data from different setups. Sensitivity function models can now be computed relative to the flat-field spectrum. Improvements in 2D coaddition Fix a bug in pypeit_setup_coadd2d for the output file name of the .coadd2d file Added possibility to specify more than one Science folder in pypeit_setup_coadd2d Now only_slits parameter in pypeit_coadd_2dspec includes the detector number (similar to slitspatnum) Added exclude_slits parameter in pypeit_coadd_2dspec to exclude specific slits Fix wrong RA and Dec for 2D coadded serendips Allow wavelength calibrations for specific slits/orders to be redone (instead of adopting the value from a processed calibration frame); see new redo_slits parameter. Instrument-specific Updates Adds/Improves support for Gemini/GNIRS (IFU), Keck/KCRM, Keck/ESI, MDM/Modspec, Keck/HIRES, JWST HIRES wavelength solution improvements galore Improvements for Keck/LRIS Generated wavelength templates for all the LRIS grism & grating Added FeAr line list Improved calibration association and frame typing Improved and added documentation Changes to metadata.py including commenting out, in the pypeit file, files that have frametype None (this prevent run_pypeit to crash) Added a function check_spectrograph() (currently only defined for LRIS), that checks (during pypeit_setup) if the selected spectrograph is the corrected one for the data used. Script Changes Added a script to convert a wavelength solution into something that can be placed in the reid archive. Store user-generated wavelength solution in pypeit cache Datamodel Changes Changed calibration frame naming as an attempt to avoid very long names for files with many calibration groups. Sequential numbers are reduced to a range; e.g., '0-1-2-3-4' becomes '0+4' and '3-5-6-10-11-12-15-18-19' becomes '3-5+6-10+12-15-18+19' Instrumental FWHM map is calculated and output in Calibrations and spec1d files. Under-the-hood Improvements Change how masking is dealt with in extraction to fix a bug in how masks were being treated for echelle data Refactored function that loads wavelength calibration line lists Bug Fixes Hotfix for GTC/OSIRIS lamp list Hotfix for Arc1D stats annotations on the QA Hotfix for metadata: correctly set config_independent_frames when multiple configurations are being setup support lists in config_independent_frames Hotfix for rebin (speed-up and conserves flux) Hotfix for skysub regions GUI that used np.bool Hotfix to stop pypeit_setup from crashing on data from lbt_luci1, lbt_luci2, magellan_fire, magellan_fire_long, p200_tspec, or vlt_sinfoni. Hotfix to set BPM for each type of calibration file. Fixed a bug in echelle coadding where the wrong coadded spectra were being used in final stacks. Fix a bug in spectrograph.select_detectors, where a list of slitspatnum could not be used.
  61. Kareta, T., Reddy, V., 2023, PSJ, 4, 174, Nuclear and Orbital Characterization of the Transition Object (4015) 107P/Wilson-Harrington
    Comet 107P/Wilson-Harrington, cross-listed as asteroid 4015, is one of the original transition objects whose properties do not neatly fit into a cometary or asteroidal origin. Discovered in a period of apparently gas-dominated activity in 1949, it was subsequently lost and recovered as the inactive asteroid 1979 VA. We obtained new and reanalyzed archival observations of the object, compared to meteorites, and conducted new orbital integrations in order to understand the nature of this object and to understand where it falls on the asteroid-comet continuum. Wilson-Harrington's reflectance spectrum is approximately neutral from visible to near-infrared wavelengths, but has a reflectance maximum near 0.8-0.9 m. The object's spectrum is well matched by laboratory spectra of carbonaceous chondrite meteorites like the CM Murchison or the C I Ivuna. The object's phase curve slope is compatible with either an asteroidal or cometary origin, and its recent orbital history has no periods with high enough temperatures to have altered its surface. While it is possible that some unknown process has acted to change the surface from an originally cometary one, we instead prefer a fundamentally asteroidal origin for Wilson-Harrington, which can explain its surface and orbital properties. However, this would require a way to maintain significant (hyper)volatile supplies on the near-Earth objects beyond what is currently expected. Wilson-Harrington's similar meteorite affinity and possible orbital link to sample return targets (162173) Ryugu and (101955) Bennu suggest that the returned samples from the Hayabusa-2 and OSIRIS-REx missions might hold the key to understanding this object.
  62. Stern, S., White, O., Grundy, W., et al., 2023, PSJ, 4, 176, The Properties and Origin of Kuiper Belt Object Arrokoth's Large Mounds
    We report on a study of the mounds that dominate the appearance of Kuiper Belt Object (486958) Arrokoth's larger lobe, named Wenu. We compare the geological context of these mounds and measure and intercompare their shapes, sizes/orientations, reflectance, and colors. We find the mounds are broadly self-similar in many respects and interpret them as the original building blocks of Arrokoth. It remains unclear why these building blocks are so similar in size-and this represents a new constraint and challenge for solar system formation models. We then discuss the implications of this interpretation.
  63. van Holstein, R., Keller, C., Snik, F., et al., 2023, A&A, 677, A150, Polarization-dependent beam shifts upon metallic reflection in high-contrast imagers and telescopes
    Context. To directly image rocky exoplanets in reflected (polarized) light, future space- and ground-based high-contrast imagers and telescopes aim to reach extreme contrasts at close separations from the star. However, the achievable contrast will be limited by reflection-induced polarization aberrations. While polarization aberrations can be modeled with numerical codes, these computations provide little insight into the full range of effects, their origin and characteristics, and possible ways to mitigate them.
    Aims: We aim to understand polarization aberrations produced by reflection off flat metallic mirrors at the fundamental level.
    Methods: We used polarization ray tracing to numerically compute polarization aberrations and interpret the results in terms of the polarization-dependent spatial and angular Goos-Hanchen and Imbert-Federov shifts of the beam of light as described with closed-form mathematical expressions in the physics literature.
    Results: We find that all four beam shifts are fully reproduced by polarization ray tracing. We study the origin and characteristics of the shifts as well as the dependence of their size and direction on the beam intensity profile, incident polarization state, angle of incidence, mirror material, and wavelength. Of the four beam shifts, only the spatial Goos-Hanchen and Imbert-Federov shifts are relevant for high-contrast imagers and telescopes because these shifts are visible in the focal plane and create a polarization structure in the point-spread function that reduces the performance of coronagraphs and the polarimetric speckle suppression close to the star.
    Conclusions: Our study provides a fundamental understanding of the polarization aberrations resulting from reflection off flat metallic mirrors in terms of beam shifts and lays out the analytical and numerical tools to describe these shifts. The beam shifts in an optical system can be mitigated by keeping the f-numbers large and angles of incidence small. Most importantly, mirror coatings should not be optimized for maximum reflectivity, but should be designed to have a retardance close to 180. The insights from our study can be applied to improve the performance of SPHERE-ZIMPOL at the VLT and future telescopes and instruments such as the Roman Space Telescope, the Habitable Worlds Observatory, GMagAO-X at the GMT, PSI at the TMT, and PCS (or EPICS) at the ELT.
  64. van Belle, G., Hillsberry, D., Rao-Aourpally, V., et al., 2023, AAS, 55, 107.02, MoonLITE: the Lunar InTerferometry Explorer
    The MoonLITE (Lunar InTerferometry Explorer) project is an NASA Astrophysics Pioneers proposal to develop, build, fly, and operate the first separated-aperture optical interferometer in space, delivering faint, sub-milliarcsecond science results. MoonLITE will leverage the Pioneers opportunity to fly as a hosted payload aboard NASA's Commercial Lunar Payload Services (CLPS), to deliver an optical interferometer to the lunar surface. This would enabling unprecedented discovery power, combining high spatial resolution from optical interferometry with deep sensitivity from the stability of the lunar surface. Following a CLPS landing, the CLPS rover will deploy the pre-loaded MoonLITE outboard optical element 100 meters from the lander, establishing a interferometric observatory with a single deployment. MoonLITE combines a 110 microarcsecond limiting spatial resolution with enough sensitivity to observe targets fainter than 17th magnitude in the visible. The capabilities of MoonLITE open a unique discovery space that includes direct size measurements of the smallest, coolest stars and substellar brown dwarfs; searches for close-in stellar companions orbiting exoplanet-hosting stars that could confound our understanding and characterization of the frequency of earth-like planets; direct size measurements of young stellar objects and characterization of the terrestrial planet forming regions of these young stars; measurements of the inner regions and binary fraction of active galactic nuclei; and probing the very nature of spacetime foam itself. A portion of the observing time of this revolutionary capability will be also made available to the broader community via a guest observer program. MoonLITE takes advantage of the CLPS opportunity to place an interferometer in space, on a stable platform - the lunar surface - and delivers an unprecedented combination of sensitivity and angular resolution, at the remarkably affordable cost point of Pioneers.
  65. Schindler, K., 2023, AAS, 55, 114.01, Indigenous Astronomy in Grand Canyon National Park: The Havasupai Tribe
    In 2019the 100th anniversary of Grand Canyon's designation as a national parkthe International Dark Sky Association certified Grand Canyon National Park as an International Dark Sky Park. While this heralded a new era of dark sky protection at the park, it also served as a reminder of the rich heritage of astronomical observations by the eleven indigenous tribes that maintain a historic connection to the area now encompassed by the park. One of these tribes, the Havasupai, is the only one to still live below the rim and is also the last to live in the area recently renamed from Indian Garden to Havasupai Gardens, in honor of the tribe's rich heritage there. The Havasupai relied on astronomical observations for marking the start of a new year, arrival of certain months, and the time of night. The tribe also incorporated many constellations into their mythologies.
  66. Adams, D., 2023, AAS, 55, 114.02, Two Deserts, One Dark Sky: Indigenous Arabian Astronomy at the Limits of Naked-Eye Visibility
    The 0.0-magnitude star Vega is easy to spot, but its full Arabic namean-nasr al-waqi', meaning the "Alighting Vulture"required observing the magnitude 4.3 and 5.2 stars near it. In one Arabian story, the Alighting Vulture aided the nearby Camel Mothers (al-'awa'idh) in protecting the Young Camel (ar-rub'), a magnitude 5.75 star near the limit of naked-eye visibility. Without a pristine, dark sky to activate the imagination, this story would not have existed, and today we would not be calling that 0.0-magnitude star by the name "Vega". Drawing from 6th10th century CE Arabic texts, this talk showcases the importance of dark skies to the development of the rich cultural traditions of indigenous Arabian astronomy. This original research demonstrates how dark desert skies enabled 4th, 5th and 6th magnitude stars to take prominent roles in the formation of indigenous Arabian star groupings and the stories that gave brighter stars their names.
  67. Speckert, M., Massey, P., 2023, AAS, 55, 201.06, The Stellar Content of Berkeley 50 (IC1310)
    Berkeley 50, also categorized as IC 1310, is a poorly studied star cluster. What brought our attention to this star cluster was the suggestion by Lowell astronomer Brian Skiff that a very red star in the center might be a red supergiant (RSG), which we quickly confirmed spectroscopically. To determine the membership of the stars in the cluster, we used proper motions from Gaia. Using images taken by Lowell astronomer Dr. Deidre Hunter, we did UBV photometry of the cluster members. Using the 4.3-meter Lowell Discovery Telescope, we used the DeVeny spectrograph to gather optical spectra of the 16 brightest member stars. We classified the stars as B-type dwarfs, with the exception of the RSG. The spectra also allowed us to determine the reddening, with an E(B-V)=0.9 mag. Gaia parallaxes of the spectroscopically confirmed members indicate a distance of 3.8 kpc. Using the distance and the reddening, we determined the intrinsic colors and absolute magnitudes of the members that lacked spectroscopy. From there, we were able to find the effective temperatures and the luminosities of all the known members in order to produce an HRD. We then compared the stars on the HRD to evolutionary tracks. As expected, we find that the RSG is the most luminous (and presumably most massive) star in this young cluster.
  68. Hall, J., 2023, AAS, 55, 226.03, Dark Sky Preservation in Flagstaff and in Arizona
    Dark sky protection has been a tradition in Flagstaff, Arizona for 65 years, beginning with a 1958 ordinance banning advertising searchlights in the city. In 2001, Flagstaff became the first city to be designated a Dark Sky Community by the International Dark Sky Association, and since then, several other communities and places in Arizona have achieved IDA dark sky designations. Maintaining the quality of the night sky has been an ongoing effort in policy, advocacy, and collaboration with numerous organizations, and with impacts and benefits that extend well beyond Arizona's $4.5 billion astronomy and optics industry. In this talk, I will summarize those efforts, discuss best practices for achieving dark sky protection, provide some examples of successful outcomes at the local and state levels, and offer some thoughts on how individual outcomes can serve as models for other communities.
  69. van Belle, G., Hillsberry, D., Rao-Aourpally, V., et al., 2023, AAS, 55, 236.04, Science Cases for MoonLITE: the Lunar InTerferometry Explorer
    The MoonLITE (Lunar InTerferometry Explorer) project is an NASA Astrophysics Pioneers proposal to develop, build, fly, and operate the first separated-aperture optical interferometer in space, delivering faint, sub-milliarcsecond science results. MoonLITE combines a 110 microarcsecond limiting spatial resolution with enough sensitivity to observe targets fainter than 17th magnitude in the visible. The capabilities of MoonLITE open unique discovery space for objects both near and far. The facility will make first direct size measurements of M-dwarfs later than M6, as well as brown dwarfs, will constrain linear size and effective temperature modeling for these objects. MoonLITE will search for close-in stellar companions orbiting exoplanet-hosting stars, guiding our understanding and characterization of the frequency of earth-like planets It will make direct size measurements of young stellar objects and characterize of the terrestrial planet forming regions of these young stars. MoonLITE will make measurements of the inner regions and binary fraction of active galactic nuclei It will also explore limits of the Planck length by observing point sources at increasingly cosmological distances. A portion of MoonLITE's observing time will be also made available to the broader community via a guest observer program; we anticipate the wider community will come up with other novel applications of this revolutionary capability.
  70. Sciamma-O'Brien, E., Roser, J., Boersma, C., et al., (including Grundy, W.), 2023, AAS, 55, 332.01, On the New Optical Constants Database (OCdb) and its Importance for the Interpretation of Observational Data
    The Optical Constants database (ocdb.smce.nasa.gov) came online in February 2023 and provides complex refractive indices of laboratory-generated organic refractory materials and ices relevant to (exo)planetary and astrophysical environments. The goal of the OCdb is to centralize published optical constants data to facilitate both their access by the scientific community and their use to analyze observational data returned by space missions and ground-based observatories. Computational tools are also under development to facilitate scientific use of the available OCdb optical constants data sets. Investigators generating laboratory optical constants are therefore encouraged to contribute their data to OCdb in order to increase the availability of their data and to enhance the scientific effectiveness of the database. Optical constants are critical input parameters in models (e.g., radiative transfer, atmospheric, and reflectance spectral models) that are used to simulate the absorption, reflection, and scattering of light due to solid materials present in planetary and astrophysical environments (planets, their satellites, exoplanets, asteroids, comets, protoplanetary disks, etc.), and are key to the compositional interpretation of observations. We will first present the infrastructure of the OCdb and show how to use and contribute to it. We will introduce the two large NASA projects, namely, the Laboratory Astrophysics Directed Work Package and the NASA Center for Optical Constants, that have been instrumental in (i) developing the OCdb, (ii) generating planetary- and astrophysics-relevant ices and organic refractory materials from gas and ice irradiation in the laboratory, and (iii) determining their optical constants for inclusion in OCdb. We will also present two studies that are making use of these optical constants to interpret observations of Titan's atmosphere and Pluto's surface. These studies show the importance of measuring optical constants of laboratory-generated materials, and their impact on the models used to analyze and interpret astronomical observations. These studies also demonstrate the essential role of such a database and the need for optical constants of a broad range of materials and wavelengths to enable the scientific community and to maximize the scientific return from space missions (e.g., Cassini, New Horizons, SOFIA, JWST).
  71. Jung, D., Calzetti, D., Messa, M., et al., (including Hunter, D.), 2023, ApJ, 954, 136, Universal Upper End of the Stellar Initial Mass Function in the Young and Compact LEGUS Clusters
    We investigate the variation in the upper end of the stellar initial mass function (uIMF) in 375 young and compact star clusters in five nearby galaxies within ~5 Mpc. All the young stellar clusters (YSCs) in the sample have ages 4 Myr and masses above 500 M , according to standard stellar models. The YSC catalogs were produced from Hubble Space Telescope images obtained as part of the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. They are used here to test whether the uIMF is universal or changes as a function of the cluster's stellar mass. We perform this test by measuring the H luminosity of the star clusters as a proxy for their ionizing photon rate, and charting its trend as a function of cluster mass. Large cluster numbers allow us to mitigate the stochastic sampling of the uIMF. The advantage of our approach relative to previous similar attempts is the use of cluster catalogs that have been selected independently of the presence of H emission, thus removing a potential sample bias. We find that the uIMF, as traced by the H emission, shows no dependence on cluster mass, suggesting that the maximum stellar mass that can be produced in star clusters is universal, in agreement with previous findings.
  72. Korolik, M., Roettenbacher, R., Fischer, D., et al., (including Llama, J.), 2023, AJ, 166, 123, Refining the Stellar Parameters of Ceti: a Pole-on Solar Analog
    To accurately characterize the planets a star may be hosting, stellar parameters must first be well determined. Ceti is a nearby solar analog and often a target for exoplanet searches. Uncertainties in the observed rotational velocities have made constraining Ceti's inclination difficult. For planet candidates from radial velocity (RV) observations, this leads to substantial uncertainties in the planetary masses, as only the minimum mass ( $m\sin i$ ) can be constrained with RV. In this paper, we used new long-baseline optical interferometric data from the CHARA Array with the MIRC-X beam combiner and extreme precision spectroscopic data from the Lowell Discovery Telescope with EXPRES to improve constraints on the stellar parameters of Ceti. Additional archival data were obtained from a Tennessee State University Automatic Photometric Telescope and the Mount Wilson Observatory HK project. These new and archival data sets led to improved stellar parameter determinations, including a limb-darkened angular diameter of 2.019 0.012 mas and rotation period of 46 4 days. By combining parameters from our data sets, we obtained an estimate for the stellar inclination of 7 7. This nearly pole-on orientation has implications for the previously reported exoplanets. An analysis of the system dynamics suggests that the planetary architecture described by Feng et al. may not retain long-term stability for low orbital inclinations. Additionally, the inclination of Ceti reveals a misalignment between the inclinations of the stellar rotation axis and the previously measured debris disk rotation axis (i disk = 35 10).
  73. Zaborowski, E., Drlica-Wagner, A., Ashmead, F., et al., (including Kuehn, K.), 2023, ApJ, 954, 68, Identification of Galaxy-Galaxy Strong Lens Candidates in the DECam Local Volume Exploration Survey Using Machine Learning
    We perform a search for galaxy-galaxy strong lens systems using a convolutional neural network (CNN) applied to imaging data from the first public data release of the DECam Local Volume Exploration Survey, which contains ~520 million astronomical sources covering ~4000 deg2 of the southern sky to a 5 point-source depth of g = 24.3, r = 23.9, i = 23.3, and z = 22.8 mag. Following the methodology of similar searches using Dark Energy Camera data, we apply color and magnitude cuts to select a catalog of ~11 million extended astronomical sources. After scoring with our CNN, the highest-scoring 50,000 images were visually inspected and assigned a score on a scale from 0 (not a lens) to 3 (very probable lens). We present a list of 581 strong lens candidates, 562 of which are previously unreported. We categorize our candidates using their human-assigned scores, resulting in 55 Grade A candidates, 149 Grade B candidates, and 377 Grade C candidates. We additionally highlight eight potential quadruply lensed quasars from this sample. Due to the location of our search footprint in the northern Galactic cap (b > 10 deg) and southern celestial hemisphere (decl. < 0 deg), our candidate list has little overlap with other existing ground-based searches. Where our search footprint does overlap with other searches, we find a significant number of high-quality candidates that were previously unidentified, indicating a degree of orthogonality in our methodology. We report properties of our candidates including apparent magnitude and Einstein radius estimated from the image separation.
  74. Pang, X., Wang, Y., Tang, S., et al., 2023, AJ, 166, 110, Binary Star Evolution in Different Environments: Filamentary, Fractal, Halo, and Tidal Tail Clusters
    Using membership of 85 open clusters from previous studies based on Gaia Data Release 3 data, we identify binary candidates in the color-magnitude diagram for systems with mass ratio q > 0.4. The binary fraction is corrected for incompleteness at different distances due to the Gaia angular resolution limit. We find a decreasing binary fraction with increasing cluster age, with substantial scatter. For clusters with a total mass >200 M , the binary fraction is independent of cluster mass. The binary fraction depends strongly on stellar density. Among the four types of cluster environments, the lowest-density filamentary and fractal stellar groups have the highest mean binary fraction: 23.6% and 23.2%, respectively. The mean binary fraction in tidal tail clusters is 20.8% and is lowest in the densest halo-type clusters: 14.8%. We find clear evidence of early disruptions of binary stars in the cluster sample. The radial binary fraction depends strongly on the clustercentric distance across all four types of environments, with the smallest binary fraction within the half-mass radius r h and increasing toward a few r h. Only hints of mass segregation are found in the target clusters. The observed amounts of mass segregation are not significant enough to generate a global effect inside the target clusters. We evaluate the bias of unresolved binary systems (assuming a primary mass of 1 M ) in 1D tangential velocity, which is 0.1-1 km s-1. Further studies are required to characterize the internal star cluster kinematics using Gaia proper motions.
  75. Samuroff, S., Mandelbaum, R., Blazek, J., et al., (including Kuehn, K.), 2023, MNRAS, 524, 2195, The Dark Energy Survey Year 3 and eBOSS: constraining galaxy intrinsic alignments across luminosity and colour space
    We present direct constraints on galaxy intrinsic alignments (IAs) using the Dark Energy Survey Year 3 (DES Y3), the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and its precursor, the Baryon Oscillation Spectroscopic Survey (BOSS). Our measurements incorporate photometric red sequence (redMaGiC) galaxies from DES with median redshift z ~ 0.2-1.0, luminous red galaxies from eBOSS at z ~ 0.8, and also an SDSS-III BOSS CMASS sample at z ~ 0.5. We measure two-point IA correlations, which we fit using a model that includes lensing, magnification, and photometric redshift error. Fitting on scales 6 Mpc h-1 < rp < 70 Mpc h-1, we make a detection of IAs in each sample, at 5-22 (assuming a simple one-parameter model for IAs). Using these red samples, we measure the IA-luminosity relation. Our results are statistically consistent with previous results, but offer a significant improvement in constraining power, particularly at low luminosity. With this improved precision, we see detectable dependence on colour between broadly defined red samples. It is likely that a more sophisticated approach than a binary red/blue split, which jointly considers colour and luminosity dependence in the IA signal, will be needed in future. We also compare the various signal components at the best-fitting point in parameter space for each sample, and find that magnification and lensing contribute $\sim 2\!-\!18~{{\ \rm per\ cent}}$ of the total signal. As precision continues to improve, it will certainly be necessary to account for these effects in future direct IA measurements. Finally, we make equivalent measurements on a sample of emission-line galaxies from eBOSS at z ~ 0.8. We constrain the non-linear alignment amplitude to be $A_1=0.07^{+0.32}_{-0.42}$ (|A1| < 0.78 at 95 per cent CL).
  76. Proudfoot, B., Grundy, W., Ragozzine, D., et al., 2023, hst, 17417, Exploring the Dynamics of Quaoar's Rings
    Recent stellar occultations have revealed a pair of enigmatic rings around the dwarf planet Quaoar. These narrow rings, which lie well outside Quaoar's Roche limit are extremely interesting targets for study into ring formation, evolution, and ring particle interactions. Quaoar and its moon Weywot, are, unfortunately, not well enough characterized to study the dynamics of the newly discovered ring system. In this 5 orbit program, we propose to study the orbit of Weywot to constrain the dynamics of Quaoar's rings. By using state-of-the-art non-Keplerian orbit fitting techniques, the additional astrometric observations obtained in this program will strongly constrain Weywot's orbit and orbital precession, as well as Quaoar's mass and shape. This will enable further study of Quaoar's rings, allowing the system to act as a touchstone for future studies of rings around TNOs. Our proposal uses a novel observing strategy to ensure the most efficient use of HST time, while still allowing us to accomplish our goals.
  77. Gregg, M., Mihos, C., Minniti, D., et al., (including West, M.), 2023, hst, 17510, The Origin of the Virgo Intergalactic Population
    The intracluster light (ICL) is a major component of galaxy clusters, and contains a record of the galaxies destroyed during hierarchical assembly of the cluster. This proposal addresses three issues critical to understanding the origin and evolution of intergalactic populations, using resolved star WFC3/IR photometry of intergalactic fields in the Virgo cluster. Foremost, we will probe the age distribution of Virgo's intracluster stars via the period distribution of bright AGB variable stars, a tool successfully deployed to study stellar populations in elliptical galaxies. By spreading the observations over 8 epochs and two HST cycles (4+4), we can determine periods and reveal the age spread of the intracluster stars, opening a new window on their origin and evolution. Second, IR color magnitude diagrams from the stacked imaging will establish the metallicity distribution function of the ICL, constraining the luminosity function and abundances of the galaxies that have been dismembered in assembling the intracluster population. Third, by observing five fields around the core of the cluster, we will trace how spatially well-mixed the ICL population is and how its age and metallicity vary across diverse environments, and thus measure its evolutionary state. While JWST will extend photometric work on the Virgo ICL, period determination of LPVs with JWST is very difficult because of its restricted visibility window in Virgo. It is therefore critical to begin these multi-cycle observations while time permits before the end of HST's lifetime.
  78. Thirouin, A., Noll, K., Sheppard, S., 2023, hst, 17524, A Deep Search for Moons around Contact Binary Trans-Neptunian Objects.
    A close/contact binary can be a small body with a bi-lobed shape (like 67P/Churyumov-Gerasimenko visited by the European Space Agency's Rosetta mission) or two objects touching in one point, as well as two objects with a small separation of less than a few hundred kilometers. The flyby of the trans-Neptunian object Arrokoth (a.k.a (486958) 2014 MU69) by the NASA New Horizons spacecraft has left us with no doubt that contact binaries do exist in the trans-Neptunian belt. Unfortunately, it is still unclear how these objects can form at the edge of our Solar System. Several models have been proposed, but none have been thoroughly tested with observations as the contact binary population remained elusive until recently. We propose a deep search for moon(s) around likely/confirmed contact binary identified through lightcurve and stellar occultation observations. The fraction of systems with/without a moon will allow us to infer which proposed formation model (if any) is more likely to reproduce the current contact binary population. These observations will (1) provide context for the New Horizons flyby of Arrokoth, (2) provide constraints for planetesimal formation, and (3) challenge the current formation models for binary/multiple systems.
  79. Massey, P., Bodansky, S., Morrell, N., et al., 2023, hst, 17527, Weighing the Most Massive Binary
    Understanding massive star evolution requires understanding massive binaries, as many massive stars are members of binary systems. In addition, orbit solutions provide the one direct measurement of a star's most fundamental property, its mass. We are proposing to measure accurate masses for NGC3603-A1, the most massive binary known, and the most luminous star in its rich cluster. Although identified as an eclipsing binary in 1984, the extreme crowding in the center of the cluster has made follow-up work difficult. An orbit using AO in the NIR on the VLT found masses of 116 Mo and 89 Mo for the two components. If correct, the primary would have a mass 50% larger than that of any other directly measured unevolved star. However, the uncertainties on these masses are quite large as the spectral features are mainly very broad, blended emission lines. An attempt to get better velocities was carried out by a competing group in Cycle 19, but the data were never published. We have analyzed these spectra, discovering that the upper Balmer lines are in absorption, and that at orbital phases near quadrature, the lines are readily resolved into two components: one from the primary and one from the secondary. Only two of their observations were taken at such phases, and the data have poor S/N. Here we propose to obtain much better data on the upper Balmer lines taken at times where we know the two components will be well resolved. This provides an efficient way to obtain accurate orbital parameters and masses for the most massive binary known. Such a system is the unevolved progenitor of the sort of merging massive black hole pairs indicated by recent gravitational wave detections.
  80. Massey, P., Hillier, D., Morrell, N., et al., 2023, hst, 17553, The Nature of a Newly Discovered Wolf-Rayet Binary: Archetype of Stripping?
    Understanding massive star evolution is important for a variety of astrophysical processes, from the formation of the elements to the generation of gravitational waves as their remnants merge. Wolf-Rayet (WR) stars are evolved stars, where the hydrogen has been removed from a massive OB star, and its nuclear burning products revealed at the surface. This stripping can occur either by stellar winds or by interactions in close binaries. Although we expect the latter to be an important mechanism, there are few examples where one can argue which mechanism has been responsible, as single WRs may have formed through binary interaction, but merged with its companion. Given the large number of massive stars in binaries, we expect stripped remnants to be common. Binary models suggest these should look like WRs, but they are curiously absent where we expect to find them. However, the recent discovery of a WR binary in the LMC matches many of the properties expected for a stripped binary WR. We have obtained extensive ground-based photometry and spectroscopy of this object, and have carried the analysis as far as it is possible. The WR component is of WN4-type, but with intrinsic hydrogen and helium absorption lines. The companion is an "impossible" star, with a sub-solar mass and radius but a very high temperature. We suggest that this is the result of an Algol-like system, with both components having been donors and recipients at some point. This could be the archetype of binary-produced WRs. ULLYSES obtained UV spectra of this star, and analysis of these data will allow us to determine CNO abundances, stellar wind properties, and other physical properties of this unique star.
  81. Meyer, A., Agrusa, H., Richardson, D., et al., (including Moskovitz, N.), 2023, PSJ, 4, 141, The Perturbed Full Two-body Problem: Application to Post-DART Didymos
    With the successful impact of the NASA Double Asteroid Redirection Test (DART) spacecraft in the Didymos-Dimorphos binary asteroid system, we provide an initial analysis of the post-impact perturbed binary asteroid dynamics. To compare our simulation results with observations, we introduce a set of "observable elements" calculated using only the physical separation of the binary asteroid, rather than traditional Keplerian elements. Using numerical methods that treat the fully spin-orbit-coupled dynamics, we estimate the system's mass and the impact-induced changes in orbital velocity, semimajor axis, and eccentricity. We find that the changes to the mutual orbit depend strongly on the separation distance between Didymos and Dimorphos at the time of impact. If Dimorphos enters a tumbling state after the impact, this may be observable through changes in the system's eccentricity and orbit period. We also find that any DART-induced reshaping of Dimorphos would generally reduce the required change in orbital velocity to achieve the measured post-impact orbit period, and will be assessed by the ESA Hera mission in 2027.
  82. Chandler, C., Oldroyd, W., Trujillo, C., et al., (including Kueny, J.), 2023, RNAAS, 7, 170, Erratum: "A Jupiter-family Comet Discovery via Citizen Science: 2005 XR132" (2023, RNAAS, 7, 146)
    No abstract found.
  83. Neugent, K., Massey, P., 2023, AJ, 166, 68, Newly Discovered Wolf-Rayet Stars in M31
    The evolved massive star populations of the Local Group galaxies are generally thought to be well understood. However, recent work has suggested that the Wolf-Rayet (WR) content of M31 may have been underestimated. We therefore began a pilot project to search for new WRs in M31 and to reexamine the completeness of our previous WR survey, finished almost a decade prior. Our improved imaging data and spectroscopic follow-up confirmed 19 new WRs across three small fields in M31. These newly discovered WRs are generally fainter than the previously known sample due to slightly increased reddening as opposed to intrinsic faintness. From these findings, we estimate that there are another ~60 WRs left to be discovered in M31; however, the overall ratio of WN-type (nitrogen-rich) to WC-type (carbon-rich) WRs remains unchanged with our latest additions to the M31 WR census. We are in the process of extending this pilot WR survey to include the rest of M31, and a more complete population will be detailed in our future work.
  84. Brewer, J., Zhao, L., Fischer, D., et al., (including Llama, J.), 2023, AJ, 166, 46, EXPRES. IV. Two Additional Planets Orbiting Coronae Borealis Reveal Uncommon System Architecture
    Thousands of exoplanet detections have been made over the last 25 years using Doppler observations, transit photometry, direct imaging, and astrometry. Each of these methods is sensitive to different ranges of orbital separations and planetary radii (or masses). This makes it difficult to fully characterize exoplanet architectures and to place our solar system in context with the wealth of discoveries that have been made. Here, we use the EXtreme PREcision Spectrograph to reveal planets in previously undetectable regions of the mass-period parameter space for the star Coronae Borealis. We add two new planets to the previously known system with one hot Jupiter in a 39 day orbit and a warm super-Neptune in a 102 day orbit. The new detections include a temperate Neptune planet ( $M\sin i\sim 20$ M ) in a 281.4 day orbit and a hot super-Earth ( $M\sin i=3.7$ M ) in a 12.95 day orbit. This result shows that details of planetary system architectures have been hiding just below our previous detection limits; this signals an exciting era for the next generation of extreme precision spectrographs.
  85. Hofgartner, J., Buratti, B., Beyer, R., et al., (including Grundy, W.), 2023, PSJ, 4, 132, Bolometric Hemispherical Albedo Map of Pluto from New Horizons Observations
    The New Horizons encounter with the Pluto system revealed Pluto to have an extremely spatially variable surface with expansive dark, bright, and intermediate terrains, refractory and volatile ices, and ongoing/recent endogenous and exogenous processes. Albedo is useful for understanding volatile transport because it quantifies absorbed solar energy; albedo may also provide insights into surface processes. Four filters of the New Horizons LORRI and MVIC imagers are used to approximate the bolometric (flux-weighted, wavelength-integrated) albedo. The bolometric hemispherical albedo (local energy balance albedo) as a function of the incidence angle of the solar illumination is measured for both Cthulhu and Sputnik Planitia, which are extensive, extreme dark and extreme bright terrains on Pluto. For both terrains, the bolometric hemispherical albedo increases by >30% from 0 to 90 incidence. The incidence-angle-average bolometric hemispherical albedo of Cthulhu is 0.12 0.01, and that of Sputnik Planitia is 0.80 0.06, where uncertainties are estimates based on scatter from different photometric functional approximations. The bolometric Bond albedo (global energy balance albedo) of Cthulhu is 0.12 0.01, and that of Sputnik Planitia is 0.80 0.07. A map of Pluto's incidence-angle-average bolometric hemispherical albedo is produced. The incidence-angle-average bolometric hemispherical albedo, spatially averaged over areas north of 30 S, is 0.54. Pluto has three general albedo categories: (1) very low albedo southern equatorial terrains, including Cthulhu; (2) high-albedo terrains, which constitute most of Pluto's surface; and (3) very high albedo terrains, including Sputnik Planitia. Pluto's extraordinary albedo variability with location is also spatially sharp at some places.
  86. Mallaby-Kay, M., Amodeo, S., Hill, J., et al., (including Kuehn, K.), 2023, PhRvD, 108, 023516, Kinematic Sunyaev-Zel'dovich effect with ACT, DES, and BOSS: A novel hybrid estimator
    The kinematic and thermal Sunyaev-Zel'dovich (kSZ and tSZ) effects probe the abundance and thermodynamics of ionized gas in galaxies and clusters. We present a new hybrid estimator to measure the kSZ effect by combining cosmic microwave background temperature anisotropy maps with photometric and spectroscopic optical survey data. The method interpolates a velocity reconstruction from a spectroscopic catalog at the positions of objects in a photometric catalog, which makes it possible to leverage the high number density of the photometric catalog and the precision of the spectroscopic survey. Combining this hybrid kSZ estimator with a measurement of the tSZ effect simultaneously constrains the density and temperature of free electrons in the photometrically selected galaxies. Using the 1000 deg2 of overlap between the Atacama Cosmology Telescope (ACT) Data Release 5, the first three years of data from the Dark Energy Survey (DES), and the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12, we detect the kSZ signal at 4.8 and reject the null (no-kSZ) hypothesis at 5.1 . This corresponds to 2.0 per 100,000 photometric objects with a velocity field based on a spectroscopic survey with 1 /5th the density of the photometric catalog. For comparison, a recent ACT analysis using exclusively spectroscopic data from BOSS measured the kSZ signal at 2.1 per 100,000 objects. Our derived constraints on the thermodynamic properties of the galaxy halos are consistent with previous measurements. With future surveys, such as the Dark Energy Spectroscopic Instrument and the Rubin Observatory Legacy Survey of Space and Time, we expect that this hybrid estimator could result in measurements with significantly better signal-to-noise than those that rely on spectroscopic data alone.
  87. Prato, L., Simon, M., 2023, RNAAS, 7, 150, Evolution of Circumstellar Disks around T Tauri Stars as a Function of Stellar Age
    We analyzed the distribution of surface gravities, $\mathrm{log}\,g$ , of a sample of classical T Tauri stars in Taurus to examine the relationship between stellar ages and circumstellar disk evolution. This is critical to understanding the timescales for planet formation. Given the uncertainties in $\mathrm{log}\,g$ , we find no distinction between the ages of stars with and without disks beyond that identified previously. This approach, while avoiding the contamination that plagues young star luminosity measurements, will require precisions in $\mathrm{log}\,g$ of 0.05 dex or better to be effective.
  88. Landman, R., Snellen, I., Keller, C., et al., 2023, A&A, 675, A157, Trade-offs in high-contrast integral field spectroscopy for exoplanet detection and characterisation. Young gas giants in emission
    Context. Combining high-contrast imaging with medium- or high-resolution integral field spectroscopy has the potential to boost the detection rate of exoplanets, especially at small angular separations. Furthermore, it immediately provides a spectrum of the planet that can be used to characterise its atmosphere. The achievable spectral resolution, wavelength coverage, and FOV of such an instrument are limited by the number of available detector pixels.
    Aims: We aim to study the effect of the spectral resolution, wavelength coverage, and FOV on the detection and characterisation potential of medium- to high-resolution integral field spectrographs with molecule mapping.
    Methods: The trade-offs are studied through end-to-end simulations of a typical high-contrast imaging instrument, analytical considerations, and atmospheric retrievals. The results are then validated with archival VLT/SINFONI data of the planet Pictoris b.
    Results: We show that molecular absorption spectra generally have decreasing power towards higher spectral resolution and that molecule mapping is already powerful for moderate resolutions (R 300). When choosing between wavelength coverage and spectral resolution for a given number of spectral bins, it is best to first increase the spectral resolution until R ~ 2000 and then maximise the bandwidth within an observing band. We find that T-type companions are most easily detected in the J/H band through methane and water features, while L-type companions are best observed in the H/K band through water and CO features. Such an instrument does not need to have a large FOV, as most of the gain in contrast is obtained in the speckle-limited regime close to the star. We show that the same conclusions are valid for the constraints on atmospheric parameters such as the C/O ratio, metallicity, surface gravity, and temperature, while higher spectral resolution (R 10 000) is required to constrain the radial velocity and spin of the planet.
  89. Chandler, C., Oldroyd, W., Trujillo, C., et al., (including Kueny, J.), 2023, RNAAS, 7, 146, A Jupiter-family Comet Discovery via Citizen Science: 2005 XR132
    We report the discovery of cometary activity associated with minor planet 2005 XR132, a finding facilitated by our NASA Partner program Active Asteroids, hosted on the Zooniverse online Citizen Science platform. Volunteers identified activity in a Dark Energy Camera image of 2005 XR132 from UT 2021 March 26, and our own investigation uncovered additional images of activity in Zwicky Transient Facility data spanning UT 2021 January 3 through March 31. 2005 XR132 has a semimajor axis a = 3.760 au, eccentricity e = 0.432, inclination i = 14.474, and a Tisserand parameter with respect to Jupiter of T J = 2.869, and thus is dynamically classified as a Jupiter-family comet.
  90. Dijkema, T., Vida, D., Bassa, C., et al., (including Moskovitz, N.), 2023, eMetN, 8, 252, GMN observations of the Crew-5 trunk reentry
    Using the cameras of the Global Meteor Network in Arizona, Colorado and New Mexico we reconstruct the reentry trajectory of the Dragon capsule trunk (Crew-5 flight) which occurred on 2023 April 27 around 08h52m UTC. We compare the preliminary trajectory to known orbital information of the object and deduce the moment of rapid reentry.
  91. Richey-Yowell, T., Shkolnik, E., Schneider, A., et al., 2023, ApJ, 951, 44, HAZMAT. IX. An Analysis of the UV and X-Ray Evolution of Low-mass Stars in the Era of Gaia
    Low-mass stars (1 M ) are some of the best candidates for hosting planets with detectable life because of these stars' long lifetimes and relative ratios of planet to star mass and radius. An important aspect of these stars to consider is the amount of ultraviolet (UV) and X-ray radiation incident on planets in the habitable zones due to the ability of UV and X-ray radiation to alter the chemistry and evolution of planetary atmospheres. In this work, we build on the results of the HAZMAT I and HAZMAT III M-star studies to determine the intrinsic UV and X-ray flux evolution with age for M stars using Gaia parallactic distances. We then compare these results to the intrinsic fluxes of K stars adapted from HAZMAT V. We find that although the intrinsic M-star UV flux is 10-100 times lower than that of K stars, the UV fluxes in their respective habitable zone are similar. However, the habitable zone X-ray flux evolutions are slightly more distinguishable with a factor of 3-15 times larger X-ray flux for late M stars than for K stars. These results suggest that there may not be a K-dwarf advantage compared to M stars in the UV, but one may still exist in the X-ray.
  92. Upsdell, E., Giles, P., Romer, A., et al., (including Kuehn, K.), 2023, MNRAS, 522, 5267, The XMM cluster survey: exploring scaling relations and completeness of the dark energy survey year 3 redMaPPer cluster catalogue
    We cross-match and compare characteristics of galaxy clusters identified in observations from two sky surveys using two completely different techniques. One sample is optically selected from the analysis of 3 years of Dark Energy Survey observations using the redMaPPer cluster detection algorithm. The second is X-ray selected from XMM observations analysed by the XMM Cluster Survey. The samples comprise a total area of 57.4 deg2, bounded by the area of four contiguous XMM survey regions that overlap the DES footprint. We find that the X-ray-selected sample is fully matched with entries in the redMaPPer catalogue, above > 20 and within 0.1 <$z$ <0.9. Conversely, only 38 per cent of the redMaPPer catalogue is matched to an X-ray extended source. Next, using 120 optically clusters and 184 X-ray-selected clusters, we investigate the form of the X-ray luminosity-temperature (LX -TX ), luminosity-richness (LX -), and temperature-richness (TX -) scaling relations. We find that the fitted forms of the LX -TX relations are consistent between the two selection methods and also with other studies in the literature. However, we find tentative evidence for a steepening of the slope of the relation for low richness systems in the X-ray-selected sample. When considering the scaling of richness with X-ray properties, we again find consistency in the relations (i.e. LX - and TX -) between the optical and X-ray-selected samples. This is contrary to previous similar works that find a significant increase in the scatter of the luminosity scaling relation for X-ray-selected samples compared to optically selected samples.
  93. Yu, Z., Martini, P., Penton, A., et al., (including Kuehn, K.), 2023, MNRAS, 522, 4132, OzDES Reverberation Mapping Programme: Mg II lags and R-L relation
    The correlation between the broad line region radius and continuum luminosity (R-L relation) of active galactic nuclei (AGNs) is critical for single-epoch mass estimates of supermassive black holes (SMBHs). At z ~ 1-2, where AGN activity peaks, the R-L relation is constrained by the reverberation mapping (RM) lags of the Mg II line. We present 25 Mg II lags from the Australian Dark Energy Survey RM project based on 6 yr of monitoring. We define quantitative criteria to select good lag measurements and verify their reliability with simulations based on both the damped random walk stochastic model and the rescaled, resampled versions of the observed light curves of local, well-measured AGN. Our sample significantly increases the number of Mg II lags and extends the R-L relation to higher redshifts and luminosities. The relative iron line strength $\mathcal {R}_{\rm Fe}$ has little impact on the R-L relation. The best-fitting Mg IIR-L relation has a slope = 0.39 0.08 with an intrinsic scatter $\sigma _{\rm rl} = 0.15^{+0.03}_{-0.02}$ . The slope is consistent with previous measurements and shallower than the H R-L relation. The intrinsic scatter of the new R-L relation is substantially smaller than previous studies and comparable to the intrinsic scatter of the H R-L relation. Our new R-L relation will enable more precise single-epoch mass estimates and SMBH demographic studies at cosmic noon.
  94. Sidhu, S., Cloutis, E., Mann, P., et al., (including Kareta, T.), 2023, Icar, 398, 115522, Spectral and mineralogical effects of heating on CM chondrite and related asteroids
    Several carbonaceous chondrites (CCs) display evidence of aqueous and thermal alteration. However, the process of thermal alteration is not fully understood. To investigate the spectral variations caused by thermal alteration, we heated powders of CM2 CCs Murchison and Jbilet Winselwan, as well as a simulant Murchison mixture (WMM) and its end members. Heating was conducted up to 1200 C, in 100 C increments under a purified nitrogen environment. We also compared the findings of our study with results of previous heating experiments conducted on CCs to better understand the effect differing conditions have on the spectral properties observed. Formation of Fe3+ oxyhydroxides and the decomposition of serpentine due to heating are confirmed by both reflectance and X-ray diffraction (XRD) data. Fe3+ oxyhydroxides features such as a steep slope in between 350 to 700 nm, and an 850 nm feature can be seen starting at 300 and 400 C, respectively. The serpentine-associated features start to decompose at 700 C and disappear by 900 C. Spectra >1000 C are generally dark and featureless and above this temperature, mafic silicate absorption bands begin to appear. Our results show that heating-induced spectral variations are evident, and the nature of these changes depends on various parameters including temperature, experimental conditions, duration of heating, sample grain size, as well as mineralogical changes accompanying heating, and heterogeneity between CCs.
  95. Prochaska, J., Hennawi, J., Westfall, K., et al., (including Ellsworth Bowers, T.), 2023, zndo, pypeit/PypeIt: Version 1.13.0
    Functionality/Performance Improvements and Additions Allow user control of the local sky subtraction window Implemented a resample algorithm when generating datacubes Sensitivity function masking and output updates Improve speed in ginga visualization of traces and added pypeit_chk_tilts. Note that this script uses an update of the tilts datamodel, so it will not work on older reductions. Fixed a bug in the variance_model calculation for combined images. Datamodel Changes Removed use of the term "master", renamed to calibration frames/files. Default output directory for calibration frames is now Calibrations. Calibration frames renamed from, e.g., MasterArc* to Arc*. Names of associated calibration frames now written to spec2d file headers. Dependency Changes Deprecate support for python 3.8 with PypeIt, allow python 3.11 Make pypeit_show_2dspec (somewhat) backwards compatible. Added the option to disable strict version checking for 1d coadds. Start to deprecate use of os.path in favor of pathlib Script Changes In PypeIt files, the 'calib' column is now always added to the pypeit file, regardless of whether or not you also request the 'comb_id' and 'bkg_id' columns. In PypeIt files, the calibration group numbers can now be anything, as long as there are no more than 63 unique integers. Deprecated pypeit_parse_calib_id script, but improved the .calib file provided by pypeit_setup. The .calib file is now always written, and provides a direct association between input raw files and output calibration files. Discussed in new docs. Added coadd2d setup script Added the possibility to use dither offsets saved in the header of the science frames for coadding 2D spectra (dithoff must be part of the spectrograph metadata). Major quicklook updates; see documentation. ql_multislit.py deprecated. Instrument-specific Updates Updates to reduction parameters for LDT/DeVeny Hotfixes Hotfix to docs to ensure pypeit_loaders api doc is generated Hotfix for KCWI when using alignment (aka ContBars) frames for the astrometric correction.
  96. Stansberry, J., Fernandez-Valenzuela, E., Rieke, M., et al., (including Grundy, W.), 2023, jwst, 4541, Search for Varuna's Satellite
    This is a proposal to confirm the existence of the candidate satellite of Varuna. Varuna is a trans-Neptunian object which may have a close-in companion (angular separationodd 0.04"), as suggested by a double periodicity in the lightcurve of Varuna. Imaging of Varuna taken with the HST High Resolution Camera (no longer available) indicated a possible companion, but there was only a single epoch, making it impossible to confirm that the companion source was orbiting Varuna. NIRCam has resolution better than the HRC in the F070W filter. We propose a series of 3 observations of Varuna to reliably confirm this putative satellite and place initial constraints on its orbital period, enabling follow-up astrometry to determine the orbit. We will also take images at F090W in order to measure the spectral slope, for comparison with the known spectrum of Varuna itself, thus providing a test of the compositional relationship between the primary and satellite.
  97. Bernstein, G., Holler, B., Navarro-Escamilla, R., et al., (including Kuehn, K.), 2023, PSJ, 4, 115, Synchronous Rotation in the (136199) Eris-Dysnomia System
    We combine photometry of Eris from a 6 month campaign on the Palomar 60 inch telescope in 2015, a 1 month Hubble Space Telescope WFC3 campaign in 2018, and Dark Energy Survey data spanning 2013-2018 to determine a light curve of definitive period 15.771 0.008 days (1 formal uncertainties), with nearly sinusoidal shape and peak-to-peak flux variation of 3%. This is consistent at part-per-thousand precision with the P = 15.785 90 0.00005 day sidereal period of Dysnomia's orbit around Eris, strengthening the recent detection of synchronous rotation of Eris by Szakats et al. with independent data. Photometry from Gaia are consistent with the same light curve. We detect a slope of 0.05 0.01 mag per degree of Eris's brightness with respect to illumination phase averaged across g, V, and r bands, intermediate between Pluto's and Charon's values. Variations of 0.3 mag are detected in Dysnomia's brightness, plausibly consistent with a double-peaked light curve at the synchronous period. The synchronous rotation of Eris is consistent with simple tidal models initiated with a giant-impact origin of the binary, but is difficult to reconcile with gravitational capture of Dysnomia by Eris. The high albedo contrast between Eris and Dysnomia remains unexplained in the giant-impact scenario.
  98. Standing, M., Sairam, L., Martin, D., et al., (including Kunovac, V.), 2023, NatAs, 7, 702, Radial-velocity discovery of a second planet in the TOI-1338/BEBOP-1 circumbinary system
    Circumbinary planets, those that orbit around both stars of a central binary star system, challenge our understanding of planet formation. With only 12 binary systems known to host circumbinary planets, identifying more of these planets, along with their physical properties, could help to discern some of the physical processes that govern planet formation. Here we analyse radial-velocity data obtained by the HARPS and ESPRESSO spectrographs and report the detection of BEBOP-1 c, a gas giant planet with a mass of 65.2 11.8 Earth masses (M) orbiting around both stars of an eclipsing binary star system with a period of 215.5 3.3 days. The system TOI-1338, hereafter referred to as BEBOP-1, which also hosts the smaller and inner transiting planet TOI-1338 b, is only the second confirmed multiplanetary circumbinary system. We do not detect TOI-1338 b with radial-velocity data alone, and we can place an upper limit on its mass of 21.8 M with 99% confidence. TOI-1338 b is amenable to atmospheric characterization using JWST, so the BEBOP-1 system has the potential to act as a benchmark for circumbinary exo-atmospheric studies.
  99. Tang, S., Stahl, A., Prato, L., et al., (including Skiff, B.), 2023, ApJ, 950, 92, Star-crossed Lovers DI Tau A and B: Orbit Characterization and Physical Properties Determination
    The stellar companion to the weak-line T Tauri star DI Tau A was first discovered by the lunar occultation technique in 1989 and was subsequently confirmed by a speckle imaging observation in 1991. It has not been detected since, despite being targeted by five different studies that used a variety of methods and spanned more than 20 yr. Here, we report the serendipitous rediscovery of DI Tau B during our Young Exoplanets Spectroscopic Survey (YESS). Using radial velocity data from YESS spanning 17 yr, new adaptive optics observations from Keck II, and a variety of other data from the literature, we derive a preliminary orbital solution for the system that effectively explains the detection and (almost all of the) non-detection history of DI Tau B. We estimate the dynamical masses of both components, finding that the large mass difference (q ~ 0.17) and long orbital period (35 yr) make the DI Tau system a noteworthy and valuable addition to studies of stellar evolution and pre-main-sequence models. With a long orbital period and a small flux ratio (f2/f1) between DI Tau A and B, additional measurements are needed for a better comparison between these observational results and pre-main-sequence models. Finally, we report an average surface magnetic field strength ( $\bar{B}$ ) for DI Tau A, of ~0.55 kG, which is unusually low in the context of young active stars.
  100. Shipp, N., Panithanpaisal, N., Necib, L., et al., (including Kuehn, K.), 2023, ApJ, 949, 44, Streams on FIRE: Populations of Detectable Stellar Streams in the Milky Way and FIRE
    We present the first detailed comparison of populations of dwarf galaxy stellar streams in cosmological simulations and the Milky Way. In particular, we compare streams identified around 13 Milky Way analogs in the FIRE-2 simulations to streams observed by the Southern Stellar Stream Spectroscopic Survey (S 5). For an accurate comparison, we produce mock Dark Energy Survey (DES) observations of the FIRE streams and estimate the detectability of their tidal tails and progenitors. The number and stellar mass distributions of detectable stellar streams is consistent between observations and simulations. However, there are discrepancies in the distributions of pericenters and apocenters, with the detectable FIRE streams, on average, forming at larger pericenters (out to >110 kpc) and surviving only at larger apocenters (40 kpc) than those observed in the Milky Way. We find that the population of high-stellar-mass dwarf galaxy streams in the Milky Way is incomplete. Interestingly, a large fraction of the FIRE streams would only be detected as intact satellites in DES-like observations, since their tidal tails have too low surface brightness to be detectable. We thus predict a population of yet-undetected tidal tails around Milky Way satellites, as well as a population of fully undetected low-surface-brightness stellar streams, and estimate their detectability with the Rubin Observatory. Finally, we discuss the causes and implications of the discrepancies between the stream populations in FIRE and the Milky Way, and explore future avenues for tests of satellite disruption in cosmological simulations.
  101. Schwamb, M., Jones, R., Yoachim, P., et al., (including Thirouin, A.), 2023, ApJS, 266, 22, Tuning the Legacy Survey of Space and Time (LSST) Observing Strategy for Solar System Science
    The Vera C. Rubin Observatory is expected to start the Legacy Survey of Space and Time (LSST) in early to mid-2025. This multiband wide-field synoptic survey will transform our view of the solar system, with the discovery and monitoring of over five million small bodies. The final survey strategy chosen for LSST has direct implications on the discoverability and characterization of solar system minor planets and passing interstellar objects. Creating an inventory of the solar system is one of the four main LSST science drivers. The LSST observing cadence is a complex optimization problem that must balance the priorities and needs of all the key LSST science areas. To design the best LSST survey strategy, a series of operation simulations using the Rubin Observatory scheduler have been generated to explore the various options for tuning observing parameters and prioritizations. We explore the impact of the various simulated LSST observing strategies on studying the solar system's small body reservoirs. We examine what are the best observing scenarios and review what are the important considerations for maximizing LSST solar system science. In general, most of the LSST cadence simulations produce 5% or less variations in our chosen key metrics, but a subset of the simulations significantly hinder science returns with much larger losses in the discovery and light-curve metrics.
  102. Lee, J., Acevedo, M., Sako, M., et al., (including Kuehn, K.), 2023, AJ, 165, 222, The Dark Energy Survey Supernova Program: Corrections on Photometry Due to Wavelength-dependent Atmospheric Effects
    Wavelength-dependent atmospheric effects impact photometric supernova flux measurements for ground-based observations. We present corrections on supernova flux measurements from the Dark Energy Survey Supernova Program's 5YR sample (DES-SN5YR) for differential chromatic refraction (DCR) and wavelength-dependent seeing, and we show their impact on the cosmological parameters w and m . We use g - i colors of Type Ia supernovae to quantify astrometric offsets caused by DCR and simulate point-spread functions (PSFs) using the GalSIM package to predict the shapes of the PSFs with DCR and wavelength-dependent seeing. We calculate the magnitude corrections and apply them to the magnitudes computed by the DES-SN5YR photometric pipeline. We find that for the DES-SN5YR analysis, not accounting for the astrometric offsets and changes in the PSF shape cause an average bias of +0.2 mmag and -0.3 mmag, respectively, with standard deviations of 0.7 mmag and 2.7 mmag across all DES observing bands (griz) throughout all redshifts. When the DCR and seeing effects are not accounted for, we find that w and m are lower by less than 0.004 0.02 and 0.001 0.01, respectively, with 0.02 and 0.01 being the 1 statistical uncertainties. Although we find that these biases do not limit the constraints of the DES-SN5YR sample, future surveys with much higher statistics, lower systematics, and especially those that observe in the u band will require these corrections as wavelength-dependent atmospheric effects are larger at shorter wavelengths. We also discuss limitations of our method and how they can be better accounted for in future surveys.
  103. Sanchez, J., Omori, Y., Chang, C., et al., (including Kuehn, K.), 2023, MNRAS, 522, 3163, Mapping gas around massive galaxies: cross-correlation of DES Y3 galaxies and Compton-y maps from SPT and Planck
    We cross-correlate positions of galaxies measured in data from the first three years of the Dark Energy Survey with Compton-y maps generated using data from the South Pole Telescope (SPT) and the Planck mission. We model this cross-correlation measurement together with the galaxy autocorrelation to constrain the distribution of gas in the Universe. We measure the hydrostatic mass bias or, equivalently, the mean halo bias-weighted electron pressure <bhPe >, using large-scale information. We find <bhPe > to be $[0.16^{+0.03}_{-0.04},0.28^{+0.04}_{-0.05},0.45^{+0.06}_{-0.10},0.54^{+0.08}_{-0.07},0.61^{+0.08}_{-0.06},0.63^{+0.07}_{-0.08}]$ meV cm-3 at redshifts z ~ [0.30, 0.46, 0.62, 0.77, 0.89, 0.97]. These values are consistent with previous work where measurements exist in the redshift range. We also constrain the mean gas profile using small-scale information, enabled by the high-resolution of the SPT data. We compare our measurements to different parametrized profiles based on the cosmo-OWLS hydrodynamical simulations. We find that our data are consistent with the simulation that assumes an AGN heating temperature of 108.5 K but are incompatible with the model that assumes an AGN heating temperature of 108.0 K. These comparisons indicate that the data prefer a higher value of electron pressure than the simulations within r500c of the galaxies' haloes.
  104. dal Ponte, M., Santiago, B., Carnero Rosell, A., et al., (including Kuehn, K.), 2023, MNRAS, 522, 1951, Ultracool dwarfs candidates based on 6 yr of the Dark Energy Survey data
    We present a sample of 19 583 ultracool dwarf candidates brighter than z 23 selected from the Dark Energy Survey DR2 coadd data matched to VHS DR6, VIKING DR5, and AllWISE covering ~ 480 deg2. The ultracool candidates were first pre-selected based on their (i-z), (z-Y), and (Y-J) colours. They were further classified using a method that compares their optical, near-infrared, and mid-infrared colours against templates of M, L, and T dwarfs. 14 099 objects are presented as new L and T candidates and the remaining objects are from the literature, including 5342 candidates from our previous work. Using this new and deeper sample of ultracool dwarf candidates we also present: 20 new candidate members to nearby young moving groups and associations, variable candidate sources and four new wide binary systems composed of two ultracool dwarfs. Finally, we also show the spectra of 12 new ultracool dwarfs discovered by our group and presented here for the first time. These spectroscopically confirmed objects are a sanity check of our selection of ultracool dwarfs and photometric classification method.
  105. Oszkiewicz, D., Troianskyi, V., Galad, A., et al., (including Skiff, B., Polakis, T., Moskovitz, N.), 2023, Icar, 397, 115520, Spins and shapes of basaltic asteroids and the missing mantle problem
    Basaltic V-type asteroids are common in the inner part of the Main Asteroid Belt and much less abundant in the mid and outer parts. They are of scientific interest because they sample crusts and mantles of theoretically plentiful differentiated planetesimals that existed in the Solar System four billion years ago. Some Solar System theories suggest that those objects formed in the terrestrial planet region and were then implanted in the main asteroid belt. In consequence, we should observe a large number of fragments of multiple differentiated planetesimals in the inner Main Belt. That region of the Asteroid Belt is filled with V-type fragments; however, they are difficult to tell apart from typical Vestoids and Vesta fugitives. In this work, we focus on physical and dynamical characterization of V-types in the inner Main-Belt and aim to reconcile those properties with the planetesimal formation and evolution theories.

    We conducted an observing campaign over the years 2013-2022 and obtained photometric observations of V-type asteroids located mostly outside the Vesta family at specific locations of the inner Main Belt (the so-called Cells I and II). The total number of partial dense photometric lightcurves obtained in this study was 2910. We were able to model 100 V-types. We further supplement those data with 133 spins of V-types from the DAMIT database and 237 objects derived from Gaia DR3 (Durech & Hanus 2023). We found 78% 11% and 38% 13% retrograde rotators in Cell I and II, respectively. This statistic is remarkably consistent with the numerical simulations of the escape paths of Vesta fugitives that predict 81% retrograde rotators in Cell I and 40% in Cell II after the dynamical integration of 2 Gys. Based on our statistics we conclude that if there are non-Vestoids in the inner main belt, they are likely to be very few. This is consistent with the small fraction of anomalous HED meteorites in meteorite collections, small number of non-Vestoids in the middle and outer Main Belt and points to planetesimal formation location close to the Sun.

  106. Duck, A., Martin, D., Gill, S., et al., (including Kunovac, V.), 2023, MNRAS, 521, 6305, The EBLM project X. Benchmark masses, radii, and temperatures for two fully convective M-dwarfs using K2
    M-dwarfs are the most abundant stars in the galaxy and popular targets for exoplanet searches. However, their intrinsic faintness and complex spectra inhibit precise characterization. We only know of dozens of M-dwarfs with fundamental parameters of mass, radius, and effective temperature characterized to better than a few per cent. Eclipsing binaries remain the most robust means of stellar characterization. Here we present two targets from the Eclipsing Binary Low Mass (EBLM) survey that were observed with K2: EBLM J0055-00 and EBLM J2217-04. Combined with HARPS and CORALIE spectroscopy, we measure M-dwarf masses with precisions better than 5 per cent, radii better than 3 per cent, and effective temperatures on order 1 per cent. However, our fits require invoking a model to derive parameters for the primary star and fitting the M-dwarf using the transit and radial velocity observations. By investigating three popular stellar models, we determine that the model uncertainty in the primary star is of similar magnitude to the statistical uncertainty in the model fits of the secondary M-dwarf. Therefore, whilst these can be considered benchmark M-dwarfs, we caution the community to consider model uncertainty when pushing the limits of precise stellar characterization.
  107. Koposov, S., Erkal, D., Li, T., et al., (including Kuehn, K.), 2023, MNRAS, 521, 4936, S 5: Probing the Milky Way and Magellanic Clouds potentials with the 6D map of the Orphan-Chenab stream
    We present a 6D map of the Orphan-Chenab (OC) stream by combining the data from Southern Stellar Stream Spectroscopic Survey (S5) and Gaia. We reconstruct the proper motion, radial velocity, distance, on-sky track, and stellar density along the stream with spline models. The stream has a total luminosity of MV = -8.2 and metallicity of [Fe/H] = -1.9, similar to classical Milky Way (MW) satellites like Draco. The stream shows drastic changes in its physical width varying from 200 pc to 1 kpc, but a constant line-of-sight velocity dispersion of 5 $\mathrm{km\, s^{-1}}$. Despite the large apparent variation in the stellar number density along the stream, the flow rate of stars along the stream is remarkably constant. We model the 6D stream track by a Lagrange-point stripping method with a flexible MW potential in the presence of a moving extended Large Magellanic Cloud (LMC). This allows us to constrain the mass profile of the MW within the distance range 15.6 < r < 55.5 kpc, with the best measured enclosed mass of $(2.85\pm 0.1)\times 10^{11}\, \mathrm{\, M_\odot }$ within 32.4 kpc. Our stream measurements are highly sensitive to the LMC mass profile with the most precise measurement of its enclosed mass made at 32.8 kpc, $(7.02\pm 0.9)\times 10^{10}\, {\rm M}_\odot$. We also detect that the LMC dark matter halo extends to at least 53 kpc. The fitting of the OC stream allows us to constrain the past LMC trajectory and the degree of dynamical friction it experienced. We demonstrate that the stars in the OC stream show large energy and angular momentum spreads caused by LMC perturbation.
  108. Craig, M., Crawford, S., Seifert, M., et al., (including Ellsworth Bowers, T.), 2023, zndo, astropy/ccdproc: 2.4.1
    This minor release fixes the astropy version requirement and a bug in handling an empty ImageFileCollection: Fixes a crash when attempting to filter an already-empty ImageFileCollection, instead simply returning an empty ImageFileCollection. [#801] Fixes minimum astropy version in installation requirements. [#799]
  109. Trilling, D., Bernstein, G., Fraser, W., et al., (including Grundy, W.), 2023, jwst, 3701, Searching for ultra-faint trans-Neptunian objects in archival NIRCam calibration data
    Small objects in the outer Solar System are the most primitive relics of the formation of our Solar System. These small bodies have undergone minimal change over the last 4 billion years and record that era in their chemical and dynamical properties. The residents of this region are often referred to as trans-Neptunian objects, and they are quite difficult to study, as they are distant, have low reflectivities, and are very faint.

    We propose to measure the size distribution of trans-Neptunian objects as small as 10 km by analyzing hundreds of archival NIRCam calibration datasets. We will detect around 200 objects smaller than 50 km diameter the largest ever survey of very faint objects in the outer Solar System with the smallest objects having diameters around 5 km. We will also constrain the mean color of the faint trans-Neptunian population and compare the size distributions between dynamically cold and hot populations. All of the necessary data will be in the public archive by June 30, 2023.

  110. Benecchi, S., Fraser, W., Buie, M., et al., (including Grundy, W.), 2023, jwst, 3979, Are dark, red, small KBOs devoid of volatiles?
    As the New Horizons (NH) spacecraft transects the Kuiper belt it has been obtaining unique solar phase curves, lightcurves, and other information on numerous Kuiper belt objects (KBOs) not possible to obtain with Earth-based facilities. In this proposal we seek to use JWST/NIRCAM to fill out the spectro-photometric information available for these objects investigating for the first time their dominant surface compositions from 0.5-5m, a wavelength region not yet explored due to ground-based instrument faintness limits and telluric contamination. This project asks the question: Are dark, red, small KBOs devoid of volatiles? It samples objects from d~60-120km assuming an albedo of 0.1 and will be the only dataset available for many years to come with measured shapes and microphysical properties (acquired through high-phase angle NH observations) with which to correlate against compositional properties. The proposed observations include KBOs from all the dynamical classes and as a full sample they will provide key context and constraints for KBO formation models.
  111. Grundy, W., Cook, J., Holler, B., et al., 2023, jwst, 3991, Small Cold Classical TNOs as Witnesses of Outer Nebular Chemistry
    We propose to observe a sample of nine Cold Classical TNOs that are intermediate in size between the very small object Arrokoth explored by NASA's New Horizons mission and much larger objects observed by JWST during Cycle 1. Our purpose is to test whether Arrokoth's anomalously high abundance of methanol ice relative to water ice is typical of small Cold Classical TNOs, pointing to formation in a region of distinctly different nebular chemistry beyond the CO snow line. To learn more about this region of the nebula as well as potential size-dependent processes affecting objects that formed there, we divide our sample between two slices. The 1st slice matches Arrokoth's heliocentric distance, while varying the objects' sizes. The 2nd slice consists of objects at varying heliocentric distance but all of the same size. These two slices will enable us to determine whether or not there are systematic trends with size or with heliocentric distance, thereby shedding light on the processes responsible.
  112. French, R., McGhee-French, C., Gordon, M., et al., (including Bosh, A., Dunham, E., Levine, S.), 2023, Icar, 395, 115474, Uranus ring occultation observations: 1977-2006
    The Uranian rings were discovered serendipitously on 10 March 1977 during a stellar occultation (Elliot et al., 1977a; Millis et al., 1977), and a rich set of subsequent Earth-based occultations revealed that these narrow and sharp-edged rings were eccentric and inclined, precessing under the gravitational influence of the oblate central planet. Considerable progress has been made in understanding the observed characteristics of narrow rings and sharp edges (Nicholson et al., 2018) and their associated dynamics (Longaretti, 2018), but ever since their discovery, the Uranian rings have posed dynamical puzzles that resist simple explanations. The observational basis to address these questions for the Uranus system rests largely on occultation measurements of the narrow rings spanning nearly 30 years, beginning in 1977 and concluding most recently in 2006. Nearly all of these occultation data sets are available in digital form on NASA's Planetary Data System (PDS) Ring-Moon Systems node, but many of them have not been previously published or described in detail. This paper serves as a guide to the PDS archive and provides essential information about the observations and the methods used to determine the ring widths, mean optical depths, and occultation event times from individual occultation profiles. Additional detail is provided in the Supplementary Online Material accompanying this publication. In a companion paper (French et al., 2023b), we make use of these observations to determine the Uranus ring orbits, pole direction, and gravity field, and the orbital characteristics and masses of three small Uranian moons - Cressida, Ophelia, and Cordelia - from their forced normal modes on the rings.
  113. Trujillo, C., Chandler, C., Oldroyd, W., et al., (including Kueny, J.), 2023, RNAAS, 7, 106, Cometary Activity on Quasi-Hilda Object 2018 CZ16
    We present the discovery of activity originating from quasi-Hilda Object 2018 CZ16, a finding stemming from the Citizen Science project Active Asteroids. For 2018 CZ16 we identified a broad (~60) but short (~5) tail in archival Blanco 4 m data from Cerro Tololo Inter-American Observatory, Chile, (CTIO) Dark Energy Camera images from UT 2018 May 15, 17 and 18. Activity occurred 2 months prior to perihelion, consistent with sublimation-driven activity.
  114. Windsor, J., Robinson, T., Kopparapu, R., et al., (including LLama, J.), 2023, PSJ, 4, 94, A Radiative-convective Model for Terrestrial Planets with Self-consistent Patchy Clouds
    Clouds are ubiquitous: they arise for every solar system planet that possesses an atmosphere and have also been suggested as a leading mechanism for obscuring spectral features in exoplanet observations. As exoplanet observations continue to improve, there is a need for efficient and general planetary climate models that appropriately handle the possible cloudy atmospheric environments that arise on these worlds. We generate a new 1D radiative-convective terrestrial planet climate model that self-consistently handles patchy clouds through a parameterized microphysical treatment of condensation and sedimentation processes. Our model is general enough to recreate Earth's atmospheric radiative environment without overparameterization, while also maintaining a simple implementation that is applicable to a wide range of atmospheric compositions and physical planetary properties. We first validate this new 1D patchy-cloud radiative-convective climate model by comparing it to Earth thermal structure data and to existing climate and radiative-transfer tools. We produce partially clouded Earth-like climates with cloud structures that are representative of deep tropospheric convection and are adequate 1D representations of clouds within rocky planet atmospheres. After validation against Earth, we then use our partially clouded climate model and explore the potential climates of super-Earth exoplanets with secondary nitrogen-dominated atmospheres which we assume are abiotic. We also couple the partially clouded climate model to a full-physics, line-by-line radiative-transfer model and generate high-resolution spectra of simulated climates. These self-consistent climate-to-spectral models bridge the gap between climate modeling efforts and observational studies of rocky worlds.
  115. Chandler, C., Oldroyd, W., Hsieh, H., et al., (including Kueny, J.), 2023, RNAAS, 7, 102, New Active Asteroid (588045) 2007 FZ18
    We present evidence that, on UT 2018 February 15, main-belt asteroid (588045) 2007 FZ18 displayed cometary activity in the form of two tails, one each in the anti-solar and anti-motion directions. Activity was first identified by volunteers of the NASA Partner program Active Asteroids, a Citizen Science program hosted on the Zooniverse platform, in an image acquired with the Dark Energy Camera on the Blanco 4 m telescope at the Cerro Tololo Inter-American Observatory in Chile. Notably, (588045) 2007 FZ18 is inbound toward perihelion, so telescope observations are timely to detect a possible second activity outburst.
  116. Long, J., Males, J., Haffert, S., et al., (including Keller, C.), 2023, AJ, 165, 216, Improved Companion Mass Limits for Sirius A with Thermal Infrared Coronagraphy Using a Vector-apodizing Phase Plate and Time-domain Starlight-subtraction Techniques
    We use observations with the infrared-optimized Magellan Adaptive Optics (MagAO) system and Clio camera in 3.9 m light to place stringent mass constraints on possible undetected companions to Sirius A. We suppress the light from Sirius A by imaging it through a grating vector-apodizing phase plate coronagraph with a 180 dark region (gvAPP-180). To remove residual starlight in postprocessing, we apply a time-domain principal-components-analysis-based algorithm we call PCA-Temporal, which uses eigen time series rather than eigenimages to subtract starlight. By casting the problem in terms of eigen time series, we reduce the computational cost of postprocessing the data, enabling the use of the fully sampled data set for improved contrast at small separations. We also discuss the impact of retaining fine temporal sampling of the data on final contrast limits. We achieve postprocessed contrast limits of 1.5 10-6-9.8 10-6 outside of 0.75, which correspond to planet masses of 2.6-8.0 M J. These are combined with values from the recent literature of high-contrast imaging observations of Sirius to synthesize an overall completeness fraction as a function of mass and separation. After synthesizing these recent studies and our results, the final completeness analysis rules out 99% of 9 M J planets from 2.5 to 7 au.
  117. Koehn, B., Shelus, P., Ries, J., et al., 2023, MPEC, 2023-J103, Comet P/2022 m1 = P/2000 OZ21 Loneos-Panstarrs
    No abstract found.
  118. Kareta, T., Noonan, J., Harris, W., et al., 2023, PSJ, 4, 85, Ice, Ice, Maybe? Investigating 46P/Wirtanen's Inner Coma for Icy Grains
    The release of volatiles from comets is usually from direct sublimation of ices on the nucleus, but for very or hyperactive comets other sources have to be considered to account for the total production rates. In this work, we present new near-IR (NIR) imaging and spectroscopic observations of 46P/Wirtanen taken during its close approach to Earth on 2018 December 19 with the MMIRS instrument at the MMT Observatory to search for signatures of icy or ice-rich grains in its inner coma that might explain its previously reported excess water production. The morphology of the images does not suggest any change in grain properties within the field of view, and the NIR spectra do not show the characteristic absorption features of water ice. Using a new Markov Chain Monte Carlo-based implementation of the spectral modeling approach of Protopapa et al., we estimate the areal water ice fraction of the coma to be <0.6%. When combined with slit-corrected Af values for the J, H, and K bands and previously measured dust velocities for this comet, we estimate an icy grain production rate of less than 4.6 kg s-1. This places a strict constraint on the water production rate from pure icy grains in the coma, and in turn we find that for the 2018-2019 apparition approximately 64% of 46P's surface was actively sublimating water near perihelion. We then discuss 46P's modern properties within the context of other (formerly) hyperactive comets to understand how these complex objects evolve.
  119. Graham, K., O'Donnell, J., Silverstein, M., et al., (including Kuehn, K.), 2023, RNAAS, 7, 86, Cool Cores in Clusters of Galaxies in the Dark Energy Survey
    We search for the presence of cool cores in optically selected galaxy clusters from the Dark Energy Survey (DES) and investigate their prevalence as a function of redshift and cluster richness. Clusters were selected from the redMaPPer analysis of three years of DES observations that have archival Chandra X-ray observations, giving a sample of 99 clusters with a redshift range of 0.11 < z < 0.87 and a richness range of 25 < < 207. Using the X-ray data, the core temperature was compared to the outer temperature to identify clusters where the core temperature is a factor of 0.7 or less than the outer temperature. We found a cool core fraction of approximately 20% with no significant trend in the cool core fraction with either redshift or richness.
  120. Lemos, P., Weaverdyck, N., Rollins, R., et al., (including Kuehn, K.), 2023, MNRAS, 521, 1184, Robust sampling for weak lensing and clustering analyses with the Dark Energy Survey
    Recent cosmological analyses rely on the ability to accurately sample from high-dimensional posterior distributions. A variety of algorithms have been applied in the field, but justification of the particular sampler choice and settings is often lacking. Here, we investigate three such samplers to motivate and validate the algorithm and settings used for the Dark Energy Survey (DES) analyses of the first 3 yr (Y3) of data from combined measurements of weak lensing and galaxy clustering. We employ the full DES Year 1 likelihood alongside a much faster approximate likelihood, which enables us to assess the outcomes from each sampler choice and demonstrate the robustness of our full results. We find that the ellipsoidal nested sampling algorithm MULTINEST reports inconsistent estimates of the Bayesian evidence and somewhat narrower parameter credible intervals than the sliced nested sampling implemented in POLYCHORD. We compare the findings from MULTINEST and POLYCHORD with parameter inference from the Metropolis-Hastings algorithm, finding good agreement. We determine that POLYCHORD provides a good balance of speed and robustness for posterior and evidence estimation, and recommend different settings for testing purposes and final chains for analyses with DES Y3 data. Our methodology can readily be reproduced to obtain suitable sampler settings for future surveys.
  121. Golden-Marx, J., Zhang, Y., Ogando, R., et al., (including Kuehn, K.), 2023, MNRAS, 521, 478, Characterizing the intracluster light over the redshift range 0.2 < z < 0.8 in the DES-ACT overlap
    We characterize the properties and evolution of bright central galaxies (BCGs) and the surrounding intracluster light (ICL) in galaxy clusters identified in the Dark Energy Survey and Atacama Cosmology Telescope Survey (DES-ACT) overlapping regions, covering the redshift range 0.20 < z < 0.80. Over this redshift range, we measure no change in the ICL's stellar content (between 50 and 300 kpc) in clusters with log10(M200m,SZ/M) >14.4. We also measure the stellar mass-halo mass (SMHM) relation for the BCG+ICL system and find that the slope, , which characterizes the dependence of M200m,SZ on the BCG+ICL stellar mass, increases with radius. The outskirts are more strongly correlated with the halo than the core, which supports that the BCG+ICL system follows a two-phase growth, where recent growth (z < 2) occurs beyond the BCG's core. Additionally, we compare our observed SMHM relation results to the IllustrisTNG300-1 cosmological hydrodynamic simulations and find moderate qualitative agreement in the amount of diffuse light. However, the SMHM relation's slope is steeper in TNG300-1 and the intrinsic scatter is lower, likely from the absence of projection effects in TNG300-1. Additionally, we find that the ICL exhibits a colour gradient such that the outskirts are bluer than the core. Moreover, for the lower halo mass clusters (log10(M200m,SZ/M) < 14.59), we detect a modest change in the colour gradient's slope with lookback time, which combined with the absence of stellar mass growth may suggest that lower mass clusters have been involved in growth via tidal stripping more recently than their higher mass counterparts.
  122. Stone, Z., Shen, Y., Burke, C., et al., (including Kuehn, K.), 2023, MNRAS, 521, 836, Correction to: Optical variability of quasars with 20-year photometric light curves
    No abstract found.
  123. Quirico, E., Bacmann, A., Wolters, C., et al., (including Grundy, W.), 2023, Icar, 394, 115396, On a radiolytic origin of red organics at the surface of the Arrokoth Trans-Neptunian Object
    The classical Kuiper Belt Object (KBO) Arrokoth was surveyed by the New Horizons spacecraft on 1st January 2019, revealing a small bilobed object with a red surface, whose spectral slope lies in the average of the whole KBOs population. This red color has been assigned to reddish organic materials, either inherited from the protosolar disk during accretion, or formed through radiolytic processes in the surface due to exposure to solar or interstellar photons, Solar Wind, Solar Energetic Particles or Galactic Cosmic Rays. We report here a study investigating the radiolytic scenario, based on numerical calculations and experimental simulations run with swift heavy ions (74.8 MeV 136Xe19+ and 33.06 MeV 58Ni9+), and low-energy 105 keV 18O6+ ions on CH3OH ice, the only molecule identified at Arrokoth's surface. Calculations show that sputtering is essentially controlled by Solar Wind (H and He), and that the sputtering rate depends on the nature of the material: erosion thickness over 4.55 Gyr are a few micrometers for amorphous carbon (as an analog of red organics) and a 240 m to around 10 mm for H2O and CO ice, respectively. Chemistry within the subsurface is essentially controlled by Galactic Cosmic rays (H and He), which penetrate deep down to several tens of meters and deliver an electronic dose higher than 1 eV.atom-1 in the first meter. The electronic and elastic doses delivered by Solar Wind ions are limited to the first 10s nm of the top surface, but Solar Energetic Particles deliver high electronic doses in the first 100 m of the surface (up to 200 eV.atom-1). Experimental simulations show that irradiating methanol ice with a dose consistent with that in planetary conditions, results in the formation of reddish organic materials made of aliphatic, conjugated and unconjugated olefinic, acetylinic, carbonyl and hydroxyl groups. A similarity with irradiated simple polymers (e.g. polyethyleneglycol) and materials formed through cold plasma experiments (tholins) is observed. There is little dependence with the nature and energy of the ion. The residue recovered at room temperature was analyzed with High Resolution Mass Spectrometry (Orbitrap), revealing a complex composition with around 6596 chemical formulas and likely several tens of thousands of molecules. Altogether, these analyses support active polymerization mechanisms similar to those observed in irradiated polymers, as bond-breaking, cross-linking or formation of olefinic bonds through recombination of radicals in adjacent carbon atoms. Considering both sputtering and radiolysis, as well as material ablation due to dust bombardment reported in literature, a scenario is taking shape as the production of reddish organics deep in the subsurface, and the settling of an organic crust at the top surface through volatiles removal. The presence of methanol and absence of water, inconsistent with sputtering fractionation, remains unexplained.
  124. Malik, U., Sharp, R., Penton, A., et al., (including Kuehn, K.), 2023, MNRAS, 520, 2009, OzDES Reverberation Mapping Program: H lags from the 6-yr survey
    Reverberation mapping measurements have been used to constrain the relationship between the size of the broad-line region and luminosity of active galactic nuclei (AGN). This R-L relation is used to estimate single-epoch virial black hole masses, and has been proposed to use to standardize AGN to determine cosmological distances. We present reverberation measurements made with H from the 6-yr Australian Dark Energy Survey (OzDES) Reverberation Mapping Program. We successfully recover reverberation lags for eight AGN at 0.12 < z < 0.71, probing higher redshifts than the bulk of H measurements made to date. Our fit to the R-L relation has a slope of = 0.41 0.03 and an intrinsic scatter of = 0.23 0.02 dex. The results from our multi-object spectroscopic survey are consistent with previous measurements made by dedicated source-by-source campaigns, and with the observed dependence on accretion rate. Future surveys, including LSST, TiDES, and SDSS-V, which will be revisiting some of our observed fields, will be able to build on the results of our first-generation multi-object reverberation mapping survey.
  125. Daly, R., Ernst, C., Barnouin, O., et al., (including Moskovitz, N.), 2023, Natur, 616, 443, Successful kinetic impact into an asteroid for planetary defence
    Although no known asteroid poses a threat to Earth for at least the next century, the catalogue of near-Earth asteroids is incomplete for objects whose impacts would produce regional devastation1,2. Several approaches have been proposed to potentially prevent an asteroid impact with Earth by deflecting or disrupting an asteroid1-3. A test of kinetic impact technology was identified as the highest-priority space mission related to asteroid mitigation1. NASA's Double Asteroid Redirection Test (DART) mission is a full-scale test of kinetic impact technology. The mission's target asteroid was Dimorphos, the secondary member of the S-type binary near-Earth asteroid (65803) Didymos. This binary asteroid system was chosen to enable ground-based telescopes to quantify the asteroid deflection caused by the impact of the DART spacecraft4. Although past missions have utilized impactors to investigate the properties of small bodies5,6, those earlier missions were not intended to deflect their targets and did not achieve measurable deflections. Here we report the DART spacecraft's autonomous kinetic impact into Dimorphos and reconstruct the impact event, including the timeline leading to impact, the location and nature of the DART impact site, and the size and shape of Dimorphos. The successful impact of the DART spacecraft with Dimorphos and the resulting change in the orbit of Dimorphos7 demonstrates that kinetic impactor technology is a viable technique to potentially defend Earth if necessary.
  126. Thomas, C., Naidu, S., Scheirich, P., et al., (including Moskovitz, N., Skiff, B., Polakis, T.), 2023, Natur, 616, 448, Orbital period change of Dimorphos due to the DART kinetic impact
    The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, the secondary of near-Earth binary asteroid (65803) Didymos, and changing the orbital period of Dimorphos. A change in orbital period of approximately 7 min was expected if the incident momentum from the DART spacecraft was directly transferred to the asteroid target in a perfectly inelastic collision1, but studies of the probable impact conditions and asteroid properties indicated that a considerable momentum enhancement () was possible2,3. In the years before impact, we used lightcurve observations to accurately determine the pre-impact orbit parameters of Dimorphos with respect to Didymos4-6. Here we report the change in the orbital period of Dimorphos as a result of the DART kinetic impact to be 33.0 1.0 (3) min. Using new Earth-based lightcurve and radar observations, two independent approaches determined identical values for the change in the orbital period. This large orbit period change suggests that ejecta contributed a substantial amount of momentum to the asteroid beyond what the DART spacecraft carried.
  127. Li, J., Hirabayashi, M., Farnham, T., et al., (including Kareta, T., Moskovitz, N.), 2023, Natur, 616, 452, Ejecta from the DART-produced active asteroid Dimorphos
    Some active asteroids have been proposed to be formed as a result of impact events1. Because active asteroids are generally discovered by chance only after their tails have fully formed, the process of how impact ejecta evolve into a tail has, to our knowledge, not been directly observed. The Double Asteroid Redirection Test (DART) mission of NASA2, in addition to having successfully changed the orbital period of Dimorphos3, demonstrated the activation process of an asteroid resulting from an impact under precisely known conditions. Here we report the observations of the DART impact ejecta with the Hubble Space Telescope from impact time T + 15 min to T + 18.5 days at spatial resolutions of around 2.1 km per pixel. Our observations reveal the complex evolution of the ejecta, which are first dominated by the gravitational interaction between the Didymos binary system and the ejected dust and subsequently by solar radiation pressure. The lowest-speed ejecta dispersed through a sustained tail that had a consistent morphology with previously observed asteroid tails thought to be produced by an impact4,5. The evolution of the ejecta after the controlled impact experiment of DART thus provides a framework for understanding the fundamental mechanisms that act on asteroids disrupted by a natural impact1,6.
  128. Massey, P., Neugent, K., Morrell, N., 2023, ApJ, 947, 77, Constraints on the Binarity of the WN3/O3 Class of Wolf-Rayet Stars
    The WN3/O3 Wolf-Rayet (WR) stars were discovered as part of our survey for WRs in the Magellanic Clouds. The WN3/O3s show the emission lines of a high-excitation WN star and the absorption lines of a hot O-type star, but our prior work has shown that the absorption spectrum is intrinsic to the WR star. Their place in the evolution of massive stars remains unclear. Here we investigate the possibility that they are the products of binary evolution. Although these are not WN3+O3 V binaries, they could still harbor unseen companions. To address this possibility, we have conducted a multiyear radial velocity study of six of the nine known WN3/O3s. Our study finds no evidence of statistically significant radial velocity variations, and allows us to set stringent upper limits on the mass of any hypothetical companion star: for probable orbital inclinations, any companion with a period less than 100 days must have a mass <2M . For periods less than 10 days, any companion would have to have a mass <1M . We argue that scenarios where any such companion is a compact object are unlikely. The absorption lines indicate a normal projected rotational velocity, making it unlikely that these stars evolved with the aid of a companion star that has since merged. The modest rotation also suggests that these stars are not the result of homogenous evolution. Thus it is likely that these stars are a normal but short-lived stage in the evolution of massive stars. * This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.
  129. de Leon, J., Licandro, J., Pinilla-Alonso, N., et al., (including Moskovitz, N., Kareta, T.), 2023, A&A, 672, A174, Characterisation of the new target of the NASA Lucy mission: Asteroid 152830 Dinkinesh (1999 VD57)
    Context. The NASA Lucy mission is designed to collect data that will be used to study the very interesting population of Jupiter Trojans, which are considered to be time capsules from the time of birth of our Solar System. During its journey, the mission will pass near a main belt asteroid, Donaldjohanson. Recently, NASA announced that a new asteroid in the belt will also be visited by Lucy: 152830 Dinkinesh (1999 VD57).
    Aims: The main goal of this work is to characterise this newly selected target, asteroid Dinkinesh, in order to provide critical information to the mission team. This information includes the most likely surface composition, albedo, and size of the asteroid, which will be used to better plan the data acquisition strategy at the time of the fly-by.
    Methods: To this end, we obtained visible spectra, colour photometry, and time-series photometry for Dinkinesh using several telescopes located at different observatories. For the spectra, we used the 10.4 m Gran Telescopio Canarias (GTC) on the island of La Palma (Spain); for the colour photometry, we used the 4.3 m Lowell Discovery Telescope (LDT) near Happy Jack, Arizona (USA); and for the time-series photometry, we used the 82 cm IAC80 telescope located on the island of Tenerife (Spain). We used the visible reflectance spectrum to obtain the taxonomical class of the asteroid in order to constrain its albedo value. Colour and time-series photometry were used to compute the absolute magnitude of Dinkinesh, which was used in conjunction with an albedo estimation to constrain its size.
    Results: Both the visible spectrum and reflectance values computed from colour photometry show that Dinkinesh is an S-type asteroid; that is, it is composed mainly of silicates and some metal. According to observations carried out as part of the NEOWISE survey, S-type asteroids have a typical geometric albedo of pV = 0.223 0.073. From our time-series photometry, we obtain an asteroid mean magnitude of r' = 19.99 0.05, which provides an absolute magnitude Hr' = 17.53 0.07 assuming G = 0.19 0.25 for S-types. Using our colour-photometry, we transformed Hr' to HV = 17.48 0.05. This value of absolute magnitude combined with the geometric albedo provides a mean diameter for Dinkinesh of ~900 m, ranging between a minimum size of 542 m and a maximum size of 1309 m.
  130. Abbott, T., Aguena, M., Alarcon, A., et al., (including Kuehn, K.), 2023, PhRvD, 107, 083504, Dark Energy Survey Year 3 results: Constraints on extensions to CDM with weak lensing and galaxy clustering
    We constrain six possible extensions to the cold dark matter (CDM) model using measurements from the Dark Energy Survey's first three years of observations, alone and in combination with external cosmological probes. The DES data are the two-point correlation functions of weak gravitational lensing, galaxy clustering, and their cross-correlation. We use simulated data vectors and blind analyses of real data to validate the robustness of our results to astrophysical and modeling systematic errors. In many cases, constraining power is limited by the absence of theoretical predictions beyond the linear regime that are reliable at our required precision. The CDM extensions are dark energy with a time-dependent equation of state, nonzero spatial curvature, additional relativistic degrees of freedom, sterile neutrinos with eV-scale mass, modifications of gravitational physics, and a binned 8(z ) model which serves as a phenomenological probe of structure growth. For the time-varying dark energy equation of state evaluated at the pivot redshift we find (wp,wa)=(-0.9 9-0.17+0.28,-0.9 1.2 ) at 68% confidence with zp=0.24 from the DES measurements alone, and (wp,wa)=(-1.0 3-0.03+0.04,-0. 4-0.3+0.4) with zp=0.21 for the combination of all data considered. Curvature constraints of k=0.0009 0.0017 and effective relativistic species Neff=3.1 0-0.16+0.15 are dominated by external data, though adding DES information to external low-redshift probes tightens the k constraints that can be made without cosmic microwave background observables by 20%. For massive sterile neutrinos, DES combined with external data improves the upper bound on the mass meff by a factor of 3 compared to previous analyses, giving 95% limits of ( Neff,meff)(0.28 ,0.20 eV ) when using priors matching a comparable Planck analysis. For modified gravity, we constrain changes to the lensing and Poisson equations controlled by functions (k ,z )=0(z )/ ,0 and (k ,z )=0(z )/ ,0, respectively, to 0=0. 6-0.5+0.4 from DES alone and (0,0)=(0.04 0.05 ,0.0 8-0.19+0.21) for the combination of all data, both at 68% confidence. Overall, we find no significant evidence for physics beyond CDM .
  131. Loyd, R., Schneider, P., Jackman, J., et al., (including Llama, J.), 2023, AJ, 165, 146, Flares, Rotation, Activity Cycles, and a Magnetic Star-Planet Interaction Hypothesis for the Far-ultraviolet Emission of GJ 436
    Variability in the far-ultraviolet (FUV) emission produced by stellar activity affects photochemistry and heating in orbiting planetary atmospheres. We present a comprehensive analysis of the FUV variability of GJ 436, a field-age M2.5V star (P rot 44 days) that is orbited by a warm Neptune-sized planet (M 25 M , R 4.1 M , P orb 2.6 days). Observations at three epochs from 2012 to 2018 span nearly a full activity cycle, sample two rotations of the star and two orbital periods of the planet, and reveal a multitude of brief flares. From 2012 to 2018, the star's 7.75 0.10 yr activity cycle produced the largest observed variations, 38% 3% in the summed flux of the major FUV emission lines. In 2018, the variability due to rotation was 8% 2%. An additional 11% 1% scatter at a cadence of 10 minutes, which is treated as white noise in the fits, likely has both instrumental and astrophysical origins. Flares increased time-averaged emission by 15% over the 0.88 days of cumulative exposure, peaking as high as 25 quiescence. We interpret these flare values as lower limits given that flares too weak or too infrequent to have been observed likely exist. GJ 436's flare frequency distribution at FUV wavelengths is unusual compared to other field-age M dwarfs, exhibiting a statistically significant dearth of high-energy (>4 1028 erg) events, which we hypothesize to be the result of a magnetic star-planet interaction (SPI) triggering premature flares. If an SPI is present, GJ 436 b's magnetic field strength must be 100 G to explain the statistically insignificant increase in the orbit-phased FUV emission.
  132. Prochaska, J., Hennawi, J., Westfall, K., et al., (including Ellsworth Bowers, T.), 2023, zndo, pypeit/PypeIt: Version 1.12.2
    Instrument-specific Updates Include Gemini/GMOS mask design slurping and usage documentation New Gemini/GMOS wavelength solution Added NIRES tutorial doc reid_arxiv templates for all MMTO Blue Channel gratings and for MMTO Binospec G600 and G1000 Usage Updates Added new specutils interface Datamodel Updates Include the S/N of extracted spectra in the SpecObj datamodel Hotfixes Various bug fixes and enhancements to mmt_bluechannel and mmt_binospec support Fixed bugs when only performing calibrations and (1) calib groups are all set to 'all' or (2) anything other than '0'.
  133. Grayling, M., Gutierrez, C., Sullivan, M., et al., (including Kuehn, K.), 2023, MNRAS, 520, 684, Core-collapse supernovae in the Dark Energy Survey: luminosity functions and host galaxy demographics
    We present the luminosity functions and host galaxy properties of the Dark Energy Survey (DES) core-collapse supernova (CCSN) sample, consisting of 69 Type II and 50 Type Ibc spectroscopically and photometrically confirmed supernovae over a redshift range 0.045 < z < 0.25. We fit the observed DES griz CCSN light curves and K-correct to produce rest-frame R-band light curves. We compare the sample with lower redshift CCSN samples from Zwicky Transient Facility (ZTF) and Lick Observatory Supernova Search (LOSS). Comparing luminosity functions, the DES and ZTF samples of SNe II are brighter than that of LOSS with significances of 3.0 and 2.5, respectively. While this difference could be caused by redshift evolution in the luminosity function, simpler explanations such as differing levels of host extinction remain a possibility. We find that the host galaxies of SNe II in DES are on average bluer than in ZTF, despite having consistent stellar mass distributions. We consider a number of possibilities to explain this - including galaxy evolution with redshift, selection biases in either the DES or ZTF samples, and systematic differences due to the different photometric bands available - but find that none can easily reconcile the differences in host colour between the two samples and thus its cause remains uncertain.
  134. Cartwright, R., DeColibus, R., C. Castillo-Rogez, J., et al., (including Grundy, W.), 2023, PSJ, 4, 42, Evidence for Nitrogen-bearing Species on Umbriel: Sourced from a Subsurface Ocean, Undifferentiated Crust, or Impactors?
    Near-infrared spectra of Umbriel and the other classical Uranian moons exhibit 2.2 m absorption bands that could result from ammonia (NH3) bearing species, possibly exposed in the geologically recent past. However, Umbriel has an ancient surface with minimal evidence for recent endogenic activity, raising the possibility that more refractory species are present, and/or that NH3 is retained over long timescales. We analyzed 33 spectra of Umbriel to investigate its 2.2 m band, along with three other absorption features we identified near 2.14, 2.22, and 2.24 m. We assessed the subobserver longitudinal distributions of these four bands, finding that they are present across Umbriel and may be spatially associated with geologic features such as craters and large basins. We compared the bands to 15 candidate constituents. We found that Umbriel's 2.14 m and 2.22 m bands are most consistent with the spectral signature of organics, its 2.24 m band is best matched by NH3 ice, and its 2.2 m band is consistent with the signatures of NH3-H2O mixtures, aluminum-bearing phyllosilicates, and sodium-bearing carbonates. However, some of these candidate constituents do not match Umbriel's spectral properties in other wavelength regions, highlighting the gaps in our understanding of the Uranian moons' surface compositions. Umbriel's 2.14 m band may alternatively result from a 2 3 overtone mode of CO2 ice. If present on Umbriel, these candidate constituents could have formed in contact with an internal ocean and were subsequently exposed during Umbriel's early history. Alternatively, these constituents might have originated in an undifferentiated crust or were delivered by impactors.
  135. Shrestha, M., Sand, D., Alexander, K., et al., (including Kuehn, K.), 2023, ApJL, 946, L25, Limit on Supernova Emission in the Brightest Gamma-Ray Burst, GRB 221009A
    We present photometric and spectroscopic observations of the extraordinary gamma-ray burst (GRB) 221009A in search of an associated supernova. Some past GRBs have shown bumps in the optical light curve that coincide with the emergence of supernova spectral features, but we do not detect any significant light-curve features in GRB 221009A, nor do we detect any clear sign of supernova spectral features. Using two well-studied GRB-associated supernovae (SN 2013dx, ${M}_{r,\max }=-19.54;$ SN 2016jca, ${M}_{r,\max }=-19.04$ ) at a similar redshift as GRB 221009A (z = 0.151), we modeled how the emergence of a supernova would affect the light curve. If we assume the GRB afterglow to decay at the same rate as the X-ray data, the combination of afterglow and a supernova component is fainter than the observed GRB brightness. For the case where we assume the best-fit power law to the optical data as the GRB afterglow component, a supernova contribution should have created a clear bump in the light curve, assuming only extinction from the Milky Way. If we assume a higher extinction of E(B - V) = 1.74 mag (as has been suggested elsewhere), the supernova contribution would have been hard to detect, with a limit on the associated supernova of ${M}_{r,\max }\approx -$ 19.54. We do not observe any clear supernova features in our spectra, which were taken around the time of expected maximum light. The lack of a bright supernova associated with GRB 221009A may indicate that the energy from the explosion is mostly concentrated in the jet, leaving a lower energy budget available for the supernova.
  136. Kueny, J., Chandler, C., Devogele, M., et al., (including Moskovitz, N., Kareta, T.), 2023, PSJ, 4, 56, Implications for the Formation of (155140) 2005 UD from a New Convex Shape Model
    (155140) 2005 UD has a similar orbit to (3200) Phaethon, an active asteroid in a highly eccentric orbit thought to be the source of the Geminid meteor shower. Evidence points to a genetic relationship between these two objects, but we have yet to fully understand how 2005 UD and Phaethon could have separated into this associated pair. Presented herein are new observations of 2005 UD from five observatories that were carried out during the 2018, 2019, and 2021 apparitions. We implemented light curve inversion using our new data, as well as dense and sparse archival data from epochs in 2005-2021, to better constrain the rotational period and derive a convex shape model of 2005 UD. We discuss two equally well-fitting pole solutions ( = 116.6, = -53.6) and ( = 300.3, = -55.4), the former largely in agreement with previous thermophysical analyses and the latter interesting due to its proximity to Phaethon's pole orientation. We also present a refined sidereal period of P sid = 5.234246 0.000097 hr. A search for surface color heterogeneity showed no significant rotational variation. An activity search using the deepest stacked image available of 2005 UD near aphelion did not reveal a coma or tail but allowed modeling of an upper limit of 0.04-0.37 kg s-1 for dust production. We then leveraged our spin solutions to help limit the range of formation scenarios and the link to Phaethon in the context of nongravitational forces and timescales associated with the physical evolution of the system.
  137. Zhao, L., Kunovac, V., Brewer, J., et al., (including Llama, J.), 2023, NatAs, 7, 366, Author Correction: Measured spin-orbit alignment of ultra-short-period super-Earth 55 Cancri e
    No abstract found.
  138. Bowen, B., Reddy, V., De Florio, M., et al., (including Kareta, T.), 2023, PSJ, 4, 52, Grain Size Effects on Visible and Near-infrared (0.35-2.5 m) Laboratory Spectra of Ordinary Chondrite and HED Meteorites
    Remote spectral characterization of near-Earth asteroids (NEAs) relies on laboratory spectral calibration to constrain their surface composition, including mineral chemistry and relative mineral abundances. Often these calibrations are based on fine meteorite powders that are representative of regolith observed on large NEAs such as (433) Eros. However, spacecraft observations of smaller NEAs such as (25143) Itokawa, (101955) Bennu, and (162173) Ryugu show surfaces devoid of a thick layer of regolith and instead find variegated landscapes with millimeter-sized particles to meter-scale boulders. Here we present the results of a laboratory study to understand the effects of grain size on the spectral properties of meteorites and how this can impact ground-based characterization of NEAs. Our study focuses on ordinary chondrites (H, L, LL) and HED meteorites, as they comprise ~90% of all meteorites that fall on Earth. Compared to ordinary chondrites, the spectral band parameters of HED meteorites are less affected by changing grain size. Among the ordinary chondrites, LL chondrites are least affected, but the spectral band parameters and mineral chemistries and abundances for H and L chondrites are most affected by changing grain size. Grain size does not seem to have any significant effect on the taxonomic classification of our meteorite spectra. We also used the Hapke model to investigate trends in single-scattering albedo as a function of grain size and present equations to recover the grain size from a spectrum.
  139. Chandler, C., Oldroyd, W., Hsieh, H., et al., (including Kueny, J.), 2023, RNAAS, 7, 60, New Recurrently Active Main-belt Comet 2010 LH15
    We announce the discovery of a main-belt comet (MBC), 2010 LH15 (alternately designated 2010 TJ175). MBCs are a rare type of main-belt asteroid that display comet-like activity, such as tails or comae, caused by sublimation. Consequently, MBCs help us map the location of solar system volatiles, providing insight into the origins of material prerequisite for life as we know it. However, MBCs have proven elusive, with fewer than 20 found among the 1.1 million known main-belt asteroids. This finding derives from Active Asteroids, a NASA Partner Citizen Science program we designed to identify more of these important objects. After volunteers classified an image of 2010 LH15 as showing activity, we carried out a follow-up investigation which revealed evidence of activity from two epochs spanning nearly a decade. This discovery is timely, with 2010 LH15 inbound toward its 2024 March perihelion passage, with potential activity onset as early as late 2023.
  140. Hsieh, H., Micheli, M., Kelley, M., et al., (including Moskovitz, N., Thirouin, A.), 2023, PSJ, 4, 43, Observational Characterization of Main-belt Comet and Candidate Main-belt Comet Nuclei
    We report observations of nine main-belt comets (MBCs) or candidate MBCs, most of which were obtained when the targets were apparently inactive. We find effective nucleus radii (assuming albedos of p V = 0.05 0.02) of r n = (0.24 0.05) km for 238P/Read, r n = (0.9 0.2) km for 313P/Gibbs, r n = (0.6 0.1) km for 324P/La Sagra, r n = (1.0 0.2) km for 426P/PANSTARRS, r n = (0.5 0.1) km for 427P/ATLAS, r n < (0.3 0.1) km for P/2016 J1-A (PANSTARRS), r n < (0.17 0.04) km for P/2016 J1-B (PANSTARRS), r n (0.5 0.2) km for P/2017 S9 (PANSTARRS), recently redesignated 455P/PANSTARRS, and r n = (0.4 0.1) km for P/2019 A3 (PANSTARRS). We identify evidence of activity in observations of 238P in 2021, and find similar inferred activity onset times and net initial mass-loss rates for 238P during perihelion approaches in 2010, 2016, and 2021. P/2016 J1-A and P/2016 J1-B are also found to be active in 2021 and 2022, making them collectively the tenth MBC confirmed to be recurrently active near perihelion and therefore likely to be exhibiting sublimation-driven activity. The nucleus of 313P is found to have colors of $g^{\prime} -r^{\prime} =0.52\pm 0.05$ and $r^{\prime} -i^{\prime} =0.22\pm 0.07$ , consistent with 313P being a Lixiaohua family member. We also report nondetections of P/2015 X6 (PANSTARRS), where we conclude that its current nucleus size is likely below our detection limits (r n 0.3 km). Lastly, we find that of 17 MBCs or candidate MBCs for which nucleus sizes (or inferred parent body sizes) have been estimated, >80% have r n 1.0 km, pointing to an apparent physical preference toward small MBCs, where we suggest that Yarkovsky-O'Keefe-Radzievskii-Paddack spin-up may play a significant role in triggering and/or facilitating MBC activity.
  141. Velloso, E., Anthony, F., do Nascimento, J., et al., (including Hall, J.), 2023, ApJL, 945, L12, Multicomponent Activity Cycles Using Hilbert-Huang Analysis
    The temporal analysis of stellar activity evolution is usually dominated by a complex trade-off between model complexity and interpretability, often by neglecting the nonstationary nature of the process. Recent studies appear to indicate that the presence of multiple coexisting cycles in a single star is more common than previously thought. The correct identification of physically meaningful cyclic components in spectroscopic time series is therefore a crucial task, which cannot overlook local behaviors. Here we propose a decomposition technique that adaptively recovers amplitude- and frequency-varying components. We present our results for the solar activity as measured both by the sunspot number and the K-line emission index, and we consistently recover the Schwabe and Gleissberg cycles as well as the Gnevyshev-Ohl pattern probably related to the Hale cycle. We also recover the known 8 yr cycle for 61 Cygni A, in addition to evidence of a three-cycles-long pattern reminiscent of the Gnevyshev-Ohl rule. This is particularly interesting as we cannot discard the possibility of a relationship between the measured field polarity reversals and this Hale-like periodicity.
  142. Oldroyd, W., Chandler, C., Trujillo, C., et al., (including Kueny, J.), 2023, RNAAS, 7, 42, Comet-like Activity Discovered on Quasi-Hilda Asteroid 2009 DQ118
    We report evidence of comet-like activity on asteroid 2009 DQ118, a quasi-Hilda object near the 3:2 interior mean-motion resonance with Jupiter. This discovery was made by volunteers as part of the Active Asteroids Citizen Science project, a NASA Partner hosted on the Zooniverse platform. Follow-up archival searches yielded over 20 images of 2009 DQ118 exhibiting a comet-like tail on UT 2016 March 8 and 9 acquired with the Dark Energy Camera on the Blanco 4 m telescope at the Cerro Tololo Inter-American Observatory, Chile. These images were taken when 2009 DQ118 was near its 2016 perihelion passage. 2009 DQ118 will next reach perihelion on UT 2023 April 22; hence, the next several months are an excellent time to observe 2009 DQ118 to search for a second epoch of activity for this object.
  143. Sebastian, D., Swayne, M., Maxted, P., et al., (including Kunovac, V.), 2023, MNRAS, 519, 3546, The EBLM project - IX. Five fully convective M-dwarfs, precisely measured with CHEOPS and TESS light curves
    Eclipsing binaries are important benchmark objects to test and calibrate stellar structure and evolution models. This is especially true for binaries with a fully convective M-dwarf component for which direct measurements of these stars' masses and radii are difficult using other techniques. Within the potential of M-dwarfs to be exoplanet host stars, the accuracy of theoretical predictions of their radius and effective temperature as a function of their mass is an active topic of discussion. Not only the parameters of transiting exoplanets but also the success of future atmospheric characterization relies on accurate theoretical predictions. We present the analysis of five eclipsing binaries with low-mass stellar companions out of a subsample of 23, for which we obtained ultra-high-precision light curves using the CHEOPS satellite. The observation of their primary and secondary eclipses are combined with spectroscopic measurements to precisely model the primary parameters and derive the M-dwarfs mass, radius, surface gravity, and effective temperature estimates using the PYCHEOPS data analysis software. Combining these results to the same set of parameters derived from TESS light curves, we find very good agreement (better than 1 per cent for radius and better than 0.2 per cent for surface gravity). We also analyse the importance of precise orbits from radial velocity measurements and find them to be crucial to derive M-dwarf radii in a regime below 5 per cent accuracy. These results add five valuable data points to the mass-radius diagram of fully convective M-dwarfs.
  144. Jackman, J., Shkolnik, E., Million, C., et al., (including Richey-Yowell, T.), 2023, MNRAS, 519, 3564, Extending optical flare models to the UV: results from comparing of TESS and GALEX flare observations for M Dwarfs
    The ultraviolet (UV) emission of stellar flares may have a pivotal role in the habitability of rocky exoplanets around low-mass stars. Previous studies have used white-light observations to calibrate empirical models which describe the optical and UV flare emission. However, the accuracy of the UV predictions of models has previously not been tested. We combined TESS optical and GALEX UV observations to test the UV predictions of empirical flare models calibrated using optical flare rates of M stars. We find that the canonical 9000-K black-body model used by flare studies underestimates the GALEX near-ultraviolet (NUV) energies of field age M stars by up to a factor of 6.5 0.7 and the GALEX far-ultraviolet energies of fully convective field age M stars by 30.6 10.0. We calculated energy correction factors that can be used to bring the UV predictions of flare models closer in line with observations. We calculated pseudo-continuum flare temperatures that describe both the white-light and GALEX NUV emission. We measured a temperature of 10 700 K for flares from fully convective M stars after accounting for the contribution from UV line emission. We also applied our correction factors to the results of previous studies of the role of flares in abiogenesis. Our results show that M stars do not need to be as active as previously thought in order to provide the NUV flux required for prebiotic chemistry, however, we note that flares will also provide more FUV flux than previously modelled.
  145. Prochaska, J., Hennawi, J., Cooke, R., et al., (including Ellsworth Bowers, T.), 2023, zndo, pypeit/PypeIt: Version 1.12.0
    Functionality Improvements / User-level Updates Refactor quicklook scripts Added spectral flexure and reference frame corrections for IFU data Allow separate sky frame to be used for sky subtraction with IFU data Limit the images written to the MasterEdges file to only the trace image, mask, and detector. Instrument-specific Updates Limit LRISr header crashes Parse Keck/NIRES dither patterns, similar to MOSFIRE Started modifications and support for JWST NIRSpec Minor / Under-the-hood Updates and Bug Fixes Fixed bug that allowed science frames to be assigned to multiple instrument configurations Fixed typo related to GitHub download for offline processing OpenMP link fix Enable boxcar_radius for manual extraction Prevent flexure crash Fixed error with deprecated numpy types Improved optimization of bspline c code Introduce BitMaskArray class to ease use of bitmasks Fixed memory hogging by matplotlib when using version >= 3.6.1
  146. Radhakrishnan, V., Keller, C., Doelman, N., et al., 2023, A&A, 670, A137, Estimating non-common path aberrations with an adaptive coronagraph
    Context. The focal-plane contrast of exoplanet imagers is affected by non-common path aberrations (NCPAs) that the adaptive optics system cannot correct for because they occur after the wavefront has been measured. NCPA estimation is commonly based on the long-exposure science image. Phase retrieval algorithms are often used, and they mostly assume that the residual phase error right after the adaptive optics system and averaged over the integration time is zero. This assumption is not always correct, for instance when controlling the adaptive optics to maximize the focal-plane contrast at the location of an exoplanet, that is to say in an adaptive coronagraph. For such cases, we present a method to calculate the NCPA using the phase information derived from the wavefront sensor (WFS) data and the science focal-plane image.
    Aims: We aim to accurately estimate the NCPA phase in the presence of (residual) atmospheric turbulence with a nonzero average wavefront. We then aim to take the NCPA into account in the adaptive coronagraph controller and achieve a higher contrast.
    Methods: The WFS measures the wavefront throughout the integration time of the science image. We combine information from the recorded WFS phases to remove the effects of the nonzero average phase from the Point Spread Function (PSF) and to remove the effects of the residual turbulence averaging over time. Then we estimate the NCPA by applying a phase-diversity-based algorithm to the resulting images. Our method is currently limited to imagers with pupil-plane coronagraphs.
    Results: We are able to recover the NCPA in an adaptive coronagraph setting with 0.01 radian RMS residuals and with a residual turbulence phase error of approximately 0.4 radian RMS. When accounted for in a contrast-control scheme, the NCPA correction leads to an order of magnitude improvement of contrast and a 50% increase in Strehl ratio, in numerical simulations.
  147. Zhao, L., Kunovac, V., Brewer, J., et al., (including Llama, J.), 2023, NatAs, 7, 198, Measured spin-orbit alignment of ultra-short-period super-Earth 55 Cancri e
    A planet's orbital alignment places important constraints on how a planet formed and consequently evolved. The dominant formation pathway of ultra-short-period planets (P < 1 day) is particularly mysterious as such planets most likely formed further out, and it is not well understood what drove their migration inwards to their current positions. Measuring the orbital alignment is difficult for smaller super-Earth/sub-Neptune planets, which give rise to smaller amplitude signals. Here we present radial velocities across two transits of 55 Cancri (Cnc) e, an ultra-short-period super-Earth, observed with the Extreme Precision Spectrograph. Using the classical Rossiter-McLaughlin method, we measure 55 Cnc e's sky-projected stellar spin-orbit alignment (that is, the projected angle between the planet's orbital axis and its host star's spin axis) to be =10-20+17 with an unprojected angle of =23-12+14. The best-fit Rossiter-McLaughlin model to the Extreme Precision Spectrograph data has a radial velocity semi-amplitude of just 0.41-0.10+0.09 m s1. The spin-orbit alignment of 55 Cnc e favours dynamically gentle migration theories for ultra-short-period planets, namely tidal dissipation through low-eccentricity planet-planet interactions and/or planetary obliquity tides.
  148. Schiappucci, E., Bianchini, F., Aguena, M., et al., (including Kuehn, K.), 2023, PhRvD, 107, 042004, Measurement of the mean central optical depth of galaxy clusters via the pairwise kinematic Sunyaev-Zel'dovich effect with SPT-3G and DES
    We infer the mean optical depth of a sample of optically selected galaxy clusters from the Dark Energy Survey via the pairwise kinematic Sunyaev-Zel'dovich (KSZ) effect. The pairwise KSZ signal between pairs of clusters drawn from the Dark Energy Survey Year-3 cluster catalog is detected at 4.1 in cosmic microwave background temperature maps from two years of observations with the SPT-3G camera on the South Pole Telescope. After cuts, there are 24,580 clusters in the 1 ,400 deg2 of the southern sky observed by both experiments. We infer the mean optical depth of the cluster sample with two techniques. The optical depth inferred from the pairwise KSZ signal is e=(2.97 0.73 )10-3 , while that inferred from the thermal SZ signal is e=(2.51 0.5 5stat0.1 5syst)10-3 . The two measures agree at 0.6 . We perform a suite of systematic checks to test the robustness of the analysis.
  149. Chandler, C., Oldroyd, W., Trujillo, C., et al., (including Kueny, J.), 2023, RNAAS, 7, 27, New Active Asteroid 2015 VA108: A Citizen Science Discovery
    We announce the discovery of activity, in the form of a distinct cometary tail, emerging from main-belt asteroid 2015 VA108. Activity was first identified by volunteers of the Citizen Science project Active Asteroids (a NASA Partner). We uncovered one additional image from the same observing run which also unambiguously shows 2015 VA108 with a tail oriented between the anti-solar and anti-motion vectors that are often correlated with activity orientation on sky. Both publicly available archival images were originally acquired UT 2015 October 11 with the Dark Energy Camera (DECam) on the Blanco 4 m telescope at the Cerro Tololo Inter-American Observatory (Chile) as part of the Dark Energy Camera Legacy Survey. Activity occurred near perihelion and, combined with its residence in the main asteroid belt, 2015 VA108 is a candidate main-belt comet, an active asteroid subset known for volatile sublimation.
  150. Simon, J., Brown, T., Mutlu-Pakdil, B., et al., (including Kuehn, K.), 2023, ApJ, 944, 43, Timing the r-process Enrichment of the Ultra-faint Dwarf Galaxy Reticulum II
    The ultra-faint dwarf galaxy Reticulum II (Ret II) exhibits a unique chemical evolution history, with ${72}_{-12}^{+10}$ % of its stars strongly enhanced in r-process elements. We present deep Hubble Space Telescope photometry of Ret II and analyze its star formation history. As in other ultra-faint dwarfs, the color-magnitude diagram is best fit by a model consisting of two bursts of star formation. If we assume that the bursts were instantaneous, then the older burst occurred around the epoch of reionization, forming ~80% of the stars in the galaxy, while the remainder of the stars formed ~3 Gyr later. When the bursts are allowed to have nonzero durations, we obtain slightly better fits. The best-fitting model in this case consists of two bursts beginning before reionization, with approximately half the stars formed in a short (100 Myr) burst and the other half in a more extended period lasting 2.6 Gyr. Considering the full set of viable star formation history models, we find that 28% of the stars formed within 500 200 Myr of the onset of star formation. The combination of the star formation history and the prevalence of r-process-enhanced stars demonstrates that the r-process elements in Ret II must have been synthesized early in its initial star-forming phase. We therefore constrain the delay time between the formation of the first stars in Ret II and the r-process nucleosynthesis to be less than 500 Myr. This measurement rules out an r-process source with a delay time of several Gyr or more, such as GW170817.
  151. Chandler, C., Trujillo, C., Oldroyd, W., et al., (including Kueny, J.), 2023, RNAAS, 7, 22, Discovery of Dust Emission Activity Emanating from Main-belt Asteroid 2015 FW412
    We present the discovery of activity emanating from main-belt asteroid 2015 FW412, a finding stemming from the Citizen Science project Active Asteroids, a NASA Partner program. We identified a pronounced tail originating from 2015 FW412 and oriented in the anti-motion direction in archival Blanco 4 m (Cerro Tololo Inter-American Observatory, Chile) Dark Energy Camera images from UT 2015 April 13, 18, 19, 21 and 22. Activity occurred near perihelion, consistent with the main-belt comets (MBCs), an active asteroid subset known for sublimation-driven activity in the main asteroid belt; thus 2015 FW412 is a candidate MBC. We did not detect activity on UT 2021 December 12 using the Inamori-Magellan Areal Camera and Spectrograph on the 6.5 m Baade telescope, when 2015 FW412 was near aphelion.
  152. Baines, E., Blomquist, S., Clark, J., et al., (including Gorney, J., Maier, E., Sanborn, J., van Belle, G., von Braun, K.), 2023, AJ, 165, 41, Simultaneous Six-way Observations from the Navy Precision Optical Interferometer
    We measured the angular diameters of six stars using the six-element observing mode of the Navy Precision Optical Interferometer (NPOI) for the first time since the early 2000s. Four of the diameters ranged from 1.2 to 1.9 mas, while the two others were much smaller at approximately 0.5 mas to 0.7 mas, which are the two smallest angular diameters measured to date with the NPOI. There is a larger spread in the measurements than data obtained with three-, four-, or five-element modes, which can be attributed in part to the flux imbalance due to the combination of more than two siderostats in a single spectrograph, and also to crosstalk between multiple baselines related to nonlinearities in the fast-delay-line dither strokes. We plan to address this in the future by using the VISION beam combiner.
  153. Kelsey, L., Sullivan, M., Wiseman, P., et al., (including Kuehn, K.), 2023, MNRAS, 519, 3046, Concerning colour: The effect of environment on type Ia supernova colour in the dark energy survey
    Recent analyses have found intriguing correlations between the colour (c) of type Ia supernovae (SNe Ia) and the size of their 'mass-step', the relationship between SN Ia host galaxy stellar mass (Mstellar) and SN Ia Hubble residual, and suggest that the cause of this relationship is dust. Using 675 photometrically classified SNe Ia from the Dark Energy Survey 5-yr sample, we study the differences in Hubble residual for a variety of global host galaxy and local environmental properties for SN Ia subsamples split by their colour. We find a 3 difference in the mass-step when comparing blue (c < 0) and red (c > 0) SNe. We observe the lowest r.m.s. scatter (~0.14 mag) in the Hubble residual for blue SNe in low mass/blue environments, suggesting that this is the most homogeneous sample for cosmological analyses. By fitting for c-dependent relationships between Hubble residuals and Mstellar, approximating existing dust models, we remove the mass-step from the data and find tentative ~2 residual steps in rest-frame galaxy U - R colour. This indicates that dust modelling based on Mstellar may not fully explain the remaining dispersion in SN Ia luminosity. Instead, accounting for a c-dependent relationship between Hubble residuals and global U - R, results in 1 residual steps in Mstellar and local U - R, suggesting that U - R provides different information about the environment of SNe Ia compared to Mstellar, and motivating the inclusion of galaxy U - R colour in SN Ia distance bias correction.
  154. Myles, J., Gruen, D., Amon, A., et al., (including Kuehn, K.), 2023, MNRAS, 519, 1792, Mapping variations of redshift distributions with probability integral transforms
    We present a method for mapping variations between probability distribution functions and apply this method within the context of measuring galaxy redshift distributions from imaging survey data. This method, which we name PITPZ for the probability integral transformations it relies on, uses a difference in curves between distribution functions in an ensemble as a transformation to apply to another distribution function, thus transferring the variation in the ensemble to the latter distribution function. This procedure is broadly applicable to the problem of uncertainty propagation. In the context of redshift distributions, for example, the uncertainty contribution due to certain effects can be studied effectively only in simulations, thus necessitating a transfer of variation measured in simulations to the redshift distributions measured from data. We illustrate the use of PITPZ by using the method to propagate photometric calibration uncertainty to redshift distributions of the Dark Energy Survey Year 3 weak lensing source galaxies. For this test case, we find that PITPZ yields a lensing amplitude uncertainty estimate due to photometric calibration error within 1 per cent of the truth, compared to as much as a 30 per cent underestimate when using traditional methods.
  155. Chen, A., Arico, G., Huterer, D., et al., (including Kuehn, K.), 2023, MNRAS, 518, 5340, Constraining the baryonic feedback with cosmic shear using the DES Year-3 small-scale measurements
    We use the small scales of the Dark Energy Survey (DES) Year-3 cosmic shear measurements, which are excluded from the DES Year-3 cosmological analysis, to constrain the baryonic feedback. To model the baryonic feedback, we adopt a baryonic correction model and use the numerical package BACCOEMU to accelerate the evaluation of the baryonic non-linear matter power spectrum. We design our analysis pipeline to focus on the constraints of the baryonic suppression effects, utilizing the implication given by a principal component analysis on the Fisher forecasts. Our constraint on the baryonic effects can then be used to better model and ameliorate the effects of baryons in producing cosmological constraints from the next-generation large-scale structure surveys. We detect the baryonic suppression on the cosmic shear measurements with a ~2 significance. The characteristic halo mass for which half of the gas is ejected by baryonic feedback is constrained to be $M_c \gt 10^{13.2} \, h^{-1} \, \mathrm{M}_{\odot }$ (95 per cent C.L.). The best-fitting baryonic suppression is $\sim 5{{\ \rm per\ cent}}$ at $k=1.0 \, {\rm Mpc}\ h^{-1}$ and $\sim 15{{\ \rm per\ cent}}$ at $k=5.0 \, {\rm Mpc} \ h^{-1}$. Our findings are robust with respect to the assumptions about the cosmological parameters, specifics of the baryonic model, and intrinsic alignments.
  156. Bartlett, J., Trimble, V., Griffin, R., et al., (including Schindler, K.), 2023, AAS, 55, 99.01, Got Stuff? How We Deal with Possible Astronomical Heritage Material
    According to the adage, "One person's trash is another's treasure." When we finish a project, some resources will continue to be significant for our future research while others may no longer be relevant. How do we decide personally what is trash and what is treasure? What is our responsibility to those who might treasure our trash? While cheap, digital storage is available, retaining the bits is easy to do. For our predecessors who recorded their observations on tapes, glass plates, or paper, storage was a greater challenge. Over time, many raw observations and working notes have been discarded. Once an observation is lost, we can never recapture that unique view of space and time. While we cannot know what questions future astronomers will ask, we can envision its reuse, along with its associated metadata and algorithms. Neither raw observations nor scientific results exist without an entire ecosystem of instruments and institutions. For these, too, we must assess their status as trash or treasure and, for treasure, assign responsibility. What about instruments that have been superseded or observatory sites that have outlived their original mission? What retains scientific value? What can be re-purposed for education or outreach? What has continuing historic and cultural importance? Furthermore, we cannot and should not preserve everything; how, then, do we choose what to preserve and how best to conserve it? The AAS charged its Working Group on the Preservation of Astronomical Heritage (WGPAH) with establishing criteria and priorities for identifying heritage material and with disseminating best practices for preserving heritage resources so that our scientific legacy remains available for research, teaching, and outreach. WGPAH can help you realistically sort through the trash and treasure of astronomical research. The choices we make reflect our values and reveal the stories we want to tell ourselves. Because our scientific heritage belongs to our whole community, we welcome your participation to ensure we preserve as many stories as we can.
  157. Lincoln, E., Baron, F., van Belle, G., 2023, AAS, 55, 105.21, The Pursuit of Hierarchies: Using improved speckle algorithms to investigate high-order stellar multiples
    Results are presented from a Fall 2022 observing run on the 4.3m Lowell Discovery Telescope (LDT) searching for previously unresolved binaries with the speckle imager QWSSI as well as results from the 3.5m WIYN telescope using the speckle imager NESSI. 25 targets were selected from a list of 91 K dwarfs within 33pc that showed variable radial velocity (RV) but have not previously been spatially resolved. Using a new algorithm that combines blind deconvolution and model fitting, we can determine accurate solutions for both the position and flux ratio of these binaries, as well as probe the surrounding pixels for faint companions. K dwarfs have a multiplicity rate of 40%, with 10% the population expected to be in triple or higher-order systems. Of the 190 total targets observed to determine RV, 91 targets showed variable RV, indicating multiplicity, and two of those targets are known triples. The inferred multiplicity fraction is slightly higher than expected, but with just 2 of 190 targets in spatially resolved triple systems, only 1% of this population has been found to be in a triple or higher-order system compared to the expected 10%. In our results, we expect all 25 targets to show multiplicity, and we expect to find 3 targets with two or more companions. To validate the companion detection efficiency of this new speckle reduction algorithm, five known binaries and the two known triples were chosen from this list as control targets. Using datasets obtained from WIYN and NESSI, we compare the performance of the conventional speckle interferometry pipeline with the blind deconvolution pipeline our group is developing.
  158. Prato, L., Tofflemire, B., Krolikowski, D., et al., (including Skiff, B., Wasserman, L.), 2023, AAS, 55, 106.14, Orbits and Disks of the Young Double-Lined Spectroscopic Binaries StH 34 and V562 Ori
    StH 34 (HBC 425) and V562 Ori (JW 707) are short-period, pre-main sequence spectroscopic binaries in the Taurus and Orion star-forming regions, respectively. Both systems host circumbinary disks; in StH 34, active accretion is occurring onto one or both stars. These relatively rare double-lined, disk-bearing systems provide the opportunity to study disk structure and evolution and the accretion process in complex environments, yielding clues to the dynamics of accretion onto massive planets and to disk dissipation. We obtained echelle spectra in visible light using the McDonald Observatory Harlan J. Smith 2.7 meter telescope with the Tull spectrograph and in the near-infrared using the Lowell Discovery Telescope with the IGRINS spectrograph. With these data we measure stellar radial velocities using a spectral-line broadening function analysis and cross-correlation, and solve for the binary orbital parameters. Time-series spectra used to characterize the orbit of StH 34 (P=21 days, mass ratio ~1, mid-M spectral types, e=0.6) reveal a complex H emission line profile; the system's K2 light curve shows "dipper" behavior. We explore correlations between the orbital and gas dynamics in this young binary and find that its variability is more stochastic than the predictable periastron accretion bursts seen in the binary-accretion archetype, DQ Tau. These differences, possibly the result of the higher accretion rate in StH 34, allow us to probe the binary-disk interaction in a new regime. For V562 Ori (P=12 days, mass ratio ~1, mid-K spectral types, e=0.1), a lack of near-infrared excess in the system indicates no warm dust in close proximity to the stars and no apparent accretion; however, 3.6 and 4.5 micron data from the YSOVARS program demonstrate the presence of cool circumbinary dust. Variability in the brightness and color of the mid-infrared excess appears to correlate with the orbital period. This research was supported in part by NSF awards AST-1313399 and AST-1518081.
  159. Adams, D., 2023, AAS, 55, 121.01, From Diving Eagle to Alighting Vulture: The Origin of Vega in Arabian Astronomy
    The bright star Vega has a name that is well-known around the world, but whose meaning continues to be misunderstood. Typically presented as the "Diving Eagle", the original Arabic name for Vega an-nasr al-waqi is best interpreted as the "Alighting Vulture". Together with its partner, Altairthe Flying Vulturethese two stars were well-known to Arabian astronomy as the Two Vultures, a star name that was in use by the early 6th century CE.

    Drawing from 6th century CE pre-Islamic Arabic poetry and 9th and 10th century CE Arabic texts by Qutrub (d. 821 CE), Ibn Qutayba (d. 889 CE), and as-Sufi (d. 986 CE), this talk traces the origins and significance of the Two Vultures in indigenous Arabian astronomy and reveals the time of night and season of the year during which they were intended to be observed. This original research demonstrates the benefit of fully understanding the cultural contexts out of which even the most prominent of our modern star names have come.

  160. Massey, P., Neugent, K., Ekstrom, S., 2023, AAS, 55, 127.06, Using Luminosity Functions to Determine the Mass-Loss Rates of Red Supergiants
    One of the main uncertainties in modeling the evolution of massive stars is accounting for mass loss during the red supergiant (RSG) phase. Such mass loss shortens the lifetime of the RSG phase, and, at high values, results in these stars shedding their hydrogen-rich outer layers and evolving back towards higher temperatures before ending their lives as supernovae. It also changes the distribution of SN types expected, and possibly even the sort of compact objects left behind, depending upon how much mass is lost during earlier phases. We can measure the mass-loss rates of RSGs using IR fluxes, but these only give us the rate today. Yet, RSGs lose mass primarily episodically, as revealed by such events as the recent Great Dimming of Betelgeuse. The current generation of Geneva evolutionary models address this problem by increasing the mass-loss rates by a factor of 3 over the quiescent rates whenever the outer envelopes of their models exceed the Eddington luminosity by a factor of 5. Including these "outbursts" has the effect of increasing the amount of mass lost by a 20 solar-mass RSG by a factor of 10 integrated over the star's lifetime. There is little effect at lower luminosities and masses. However, others have argued that even the quiescent rates are too high, and proposed significantly lower rates. Fortunately, we can use our recent census of the RSG populations in M31 and M33 to investigate the matter observationally: Higher mass-loss rates will have the effect of reducing the percentage of the highest luminosity RSGs in the luminosity function. We have compared these to the predictions of the Geneva models, including a special set that were run without the enhanced supra-Eddington rates. The observations agree very well with the predictions of the models with the enhanced rates, and rule out lower mass-loss rates.

    This work was partially supported through the National Science Foundation grant AST-1612874, and by NASA through the NASA Hubble Fellowship grant HST-HF2-51516 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555

  161. Bernardinelli, P., Napier, K., Smotherman, H., et al., (including Mommert, M.), 2023, AAS, 55, 136.05, First results from the DECam Ecliptic Exploration Project (DEEP)
    The DECam Ecliptic Exploration Project (DEEP) is a survey designed to search for faint (mVR ~ 26.5) trans-Neptunian objects (TNOs) with the Dark Energy Camera (DECam) on the 4 meter Blanco telescope at CTIO. The DEEP fields are distributed along the invariable plane, and the observing strategy is such that TNOs are found in individual nights via digital tracking with a series of exposures in four hour stares, with repeated observations that maximize the recovery potential of these objects in further observing years. We will overview our first results and data release: light curves for objects detected in single exposures (as faint as mVR ~ 24), a precise measurement of the size distribution for the cold Classical Kuiper belt using over 2000 TNO candidates, and over 100 objects with well-determined multi-year orbits. Our survey simulator enables direct comparisons between our observations and models of the trans-Neptunian region, and we reject the CFEPS-L7 model of the Kuiper belt with high significance. Future releases of the DEEP data should double the total number of known TNOs.
  162. Schindler, K., 2023, AAS, 55, 147.02, Clyde Tombaugh's Extraordinary 9-Inch Telescope
    In 1928, Clyde Tombaugh completed construction of his third telescope, a 9-inch reflector. By far his best to date, this one was also noteworthy because of the array of materials from the family farm that he used to build it. The mounting includes parts from a cream separator, automobile axle, and fly wheel from some other piece of equipment, and the tube appears to be a segment of grain auger. The telescope is also an important piece of astronomy history because it was drawings Tombaugh made with this instrument that he sent to Lowell Observatory. Unbeknownst to Tombaugh, his timing was perfect because observatory Director Vesto Slipher was just then looking for an assistant to help with the revived search for a ninth planet that observatory founder Percival Lowell had begun in 1905. Slipher liked the 23-year-old and his work and hired him. Within a year, Tombaugh discovered Pluto. Years later, when Tombaugh relocated to New Mexico, he took the 9-inch with him and continued using it for the rest of his life. In June 2022, Tombaugh's descendants put the telescope up for auction. The philanthropy department at Lowell Observatory put out call to supporters and collected enough pledges to win the auction. The telescope arrived at Lowell Observatory in July and is now on permanent display in the observatory's Rotunda Museum. Staff will also occasionally take it outside at night and use it for viewing, much as Tombaugh did on his Kansas farm nearly a century ago.
  163. Huseby, L., Peacock, S., Carpenter, K., et al., (including Richey-Yowell, T.), 2023, AAS, 55, 255B.01, The Great Escape! Extreme-UV Spectra Grids for K-Type Stars
    Stellar Extreme Ultraviolet (EUV, 100-1000 A) radiation can influence factors for habitability of planets in K dwarf systems, including driving atmospheric escape and water loss from close-in exoplanets. This wavelength range is currently unobservable due to interstellar contamination and a lack of operational instruments, and so modeling EUV spectra becomes important. We investigated K stars because their atmospheric planetary O 2 and CH 4 spectral features and high planet-star contrast ratio make these systems favorable targets for atmospheric characterization. We modeled the EUV spectra of K stars using the PHOENIX atmospheric code, utilizing Hubble Space Telescope (HST) Far and Near Ultraviolet (FUV, NUV) data for semi-empirical guidance. We categorized each spectral subtype according to temperature and surface gravity and computed the photospheric contribution to each UV flux. Then upper atmosphere models, including chromosphere and transition regions, were computed, added, and compared to HST and Galaxy Evolution Explorer (GALEX) data and adjusted for flux accuracy, including increasing the number of computed non-local thermodynamic equilibrium (non-LTE) species. Strong lines in the FUV and NUV of the synthetic emission spectra that did not match HST data were masked for a more accurate integrated flux calculation. We generated grids of spectra based on the characteristics of K0-K9 stars, which revealed that individualized grids for each spectral subtype will need to be computed, rather than computing one generalized grid applicable for all K dwarf stars. This suite of models will be added to the upcoming PEGASUS (PHOENIX EUV Grid And Stellar UV Spectra) website which will be accessible to the community and searchable using GALEX data. These synthetic spectra involving the EUV can be utilized for studies of star-planet interactions and other simulations involving planet habitability, and will be influential in the identification of potentially habitable planets in K dwarf systems.
  164. Tang, S., Stahl, A., Prato, L., et al., 2023, AAS, 55, 267.13, Searching for the Youngest Hot Jupiters Around T Tauri Stars Tracing Spot Variability Using OH/Fe Line Depth Ratio
    The best way to understand planet formation is to look for planets still forming. Planetary systems that host hot Jupiters are especially intriguing because of hot Jupiters' large sizes and peculiar short orbital periods. Moreover, the formation history of hot Jupiters is vital to the development of habitable worlds. Searching for hot Jupiters around pre-main sequence stars using the radial velocity (RV) method, however, is challenging because of the strong stellar activity of the host star. Large cool spots (as large as 80% of the visible disk) can overwhelm and mimic RV signal induced by planets. The Gaussian Process Regression (GPR) technique has been used widely to isolate the RV signal produced by the stellar activity; however, prior knowledge of the stellar rotation period, and spot(s) lifetime are important for GPR to properly model the activity signal. Knowing these stellar properties is even more critical for applying GPR to young stellar systems where the RV signal from the extreme stellar activity can be several times larger than the planet. Here, we present our preliminary result on a new way to trace spot variability on the stellar surface using the OH/Fe line depth ratio. We will also present a simulation model that can reproduce the observed periodicity of the changes in the OH/Fe line depth ratio. Finally, we will use the hot Jupiters host star, CI Tau, to demonstrate how this new technique can help the community to better find exoplanets around classical T Tauris stars.
  165. O'Grady, A., Drout, M., Gaensler, B., et al., (including Neugent, K.), 2023, AAS, 55, 320.04D, Cool, Luminous, and Highly Variable Stars in the Magellanic Clouds: Implications for Thorne-Zytkow Objects and Super-AGB Stars
    The true identity of the peculiar star HV2112, located in the SMC, has been debated. Previous studies have identified it as the first strong Thorne-Zytkow Object (TZO) candidate a class of cool, luminous stars with neutron star cores while others have argued its properties are more consistent with massive or super-AGB (m/sAGB) stars, the latter of which are the most massive stars that do not undergo core collapse supernova. While these studies identified enhanced heavy element abundances in HV2112's atmosphere, it also shows extreme variability (>4 mag), which is abnormal for stars with RSG-like luminosities. We characterized the variability of HV2112 and conducted a systematic search for cool and luminous stars in the Magellanic Clouds with similar variability properties. Using light-curves from ASAS-SN we identified 29 new candidates, nine of which also possess the distinctive light-curve morphology exhibited by HV2112. In this talk we present the results of our analysis of these stars. We find that the temperatures, luminosities, periods, and masses derived from pulsation properties of these sources are consistent with predictions for m/sAGBs, with HV2112 in particular falling into the mass range of the largest sAGBs, and below the theoretical minimum mass for TZOs. Subsequently, we have assessed the presence of heavy elements and lithium in their spectra, and used their local SFH, kinematic, and radio environments to place constraints on the age of progenitor systems and evidence for past supernovae. In all cases results are consistent with an mAGB or sAGB star identity, providing important information on the transition between low and high mass stellar evolution.
  166. Hartman, Z., van Belle, G., Lepine, S., et al., (including Clark, C.), 2023, AAS, 55, 321.02, Initial Results from the Quad-camera Wavefront-sensing Six-channel Speckle Interferometer: Searching for Unresolved Companions in the Widest Low-mass Binaries
    We present initial results of an ongoing speckle imaging campaign at the Lowell Discovery Telescope using the Differential Speckle Survey Instrument (DSSI) and the Quad-camera Wavefront-sensing Six-channel Speckle Interferometer (QWSSI) to search for unresolved third members in low-mass wide binaries. Taking the SUPERWIDE Catalog, we select a sample of low-mass wide binaries with projected physical separations larger than 10,000 au, Gaia G magnitudes brighter than 15.5, and distances less than 100 pc. Using DSSI and QWSSI, we have searched 27 of these systems for unresolved components, achieving an average delta magnitude of about four at 0.1". Combining these results with a previous campaign using NESSI on the WIYN 3.5m Telescope, we find evidence of a lack of close companion detections for low-mass wide binaries when compared with the expectation that most solar-type binaries at these separations should be higher-order multiples. One possibility is that our speckle observations are not probing the entire separation range where possible companions can reside. Given that most solar-type wide binaries at these separations are higher order multiples, we suggest that there are more companions that remain unresolved, and should be detected as spectroscopic binaries. Failure to identify these elusive companions would mean that these systems are true wide binaries and not higher-order multiples.
  167. van Belle, G., von Braun, K., Ciardi, D., et al., (including Buckingham, R., Clark, C., Bucklew, W.), 2023, AAS, 55, 341.05, The PTI Giant Star Angular Size Survey: Effective Temperatures & Linear Radii
    We calculate directly determined values for effective temperature (TEFF) and radius (R) for 191 giant stars based upon high resolution angular size measurements from optical interferometry at the Palomar Testbed Interferometer (PTI). Narrow- to wide-band photometry data for the giants are used to establish bolometric fluxes and luminosities through spectral energy distribution fitting, which allow for homogeneously establishing an assessment of spectral type and dereddened V0-K0 color; these two parameters are used as calibration indices for establishing trends in TEFF and R. Spectral types range from G0III to M7.75III, V0-K0 from 1.9 to 8.5. For the V0-K0 = {1.9, 6.5} range, median TEFF uncertainties in the fit of effective temperature versus color are found to be less than 50K; over this range, TEFF drops from 5050K to 3225K. Linear sizes are found to be largely constant at 11 R from G0III to K0III, increasing linearly with subtype to 50 R at K5III, and then further increasing linearly to 150 R by M8III. Three examples of the utility of this data set are presented: first, a fully empirical Hertzsprung-Russell Diagram is constructed and examined against stellar evolution models; second, values for stellar mass are inferred based on measures of R and literature values for log g. Finally, an improved calibration of an angular size prediction tool, based upon V and K values for a star, is presented. These results have been accepted for publication in the Astrophysical Journal.
  168. Archer, H., Hunter, D., Elmegreen, B., et al., 2023, AAS, 55, 361.01, Star Formation and the Role of CO Cores in Dwarf Irregular Galaxy WLM in the Era of JWST
    Dwarf irregular (dIrr) galaxies in the local universe allow us to examine the details of star formation at low metallicity. These low metallicity environments significantly impact molecular cloud formation and structure. Molecular clouds are primarily composed of H2, which is typically traced with low rotational transitions of CO. However, both theory and observation lead us to expect that the structure of the molecular clouds at low metallicities is fundamentally different compared to that found in higher metallicity spirals. Rubio et al. (2015) mapped 10 CO cores in the Local Group dIrr galaxy WLM for the first time at an oxygen abundance 13% of solar. Archer et al. (2022) examined the environments in which these 10 - plus an additional 47 - CO cores formed in WLM and found no obvious characteristics driving the formation of the CO cores. With the spatial resolution and sensitivity offered by the JWST, we can now probe the role in the star-forming regions of resolved CO cores in WLM. In this study, we analyze JWST images of WLM from ERS Program #1334 in the F090W, F150W, F250M, and F430M filters to look for evidence of embedded star formation. We present the first results of a comparison of objects bright in the F250M filter near detected CO cores to those within and away from star forming regions.

    Funding for this work was provided by NSF to D.H. through grant AST-1907492.

  169. Tofflemire, B., Prato, L., Schaefer, G., et al., 2023, AAS, 55, 368.06, Planet Formation in the Binary Environment An ALMA Study of FO Tau
    The majority of Sun-like stars form with binary companions, and their dynamical impact profoundly shapes the formation and survival of their planetary systems. Demographic studies have shown that close binaries (a < 100 au) have suppressed planet-occurrence rates compared to single stars, yet a substantial minority of planets do form and survive at all binary separations. To identify the conditions that foster planet formation in binary systems, we have obtained high-angular-resolution, mm interferometry for a sample of disk-bearing binary systems with known orbital solutions. In this poster, we present the case study of a young binary system, FO Tau (a ~ 22 au). Our ALMA observations resolve dust continuum (1.3 mm) and gas (CO J=2-1) from each circumstellar disk allowing us to trace the dynamical interaction between the binary orbit and the planet-forming reservoir. With these data we determine individual disk orientations and masses, while placing these measurements in the context of a new binary orbital solution. Our findings suggest that the FO Tau system is relatively placid, with observations consistent with alignment between the disks and the binary orbital plane. We compare these findings to models of binary formation and evolution, and their predictions for disk retention and planet formation.
  170. Neugent, K., Massey, P., 2023, AAS, 55, 401.01, Hungry Red Supergiants: Investigating Stellar Mergers in Evolved Massive Stars
    The percentage of massive main-sequence OB stars in binary systems is high, some arguing that it may be as large as 80-100%. However the binary fraction of red supergiants (RSGs) ranges from 15-40%, despite these stars being the evolved descendants of OB stars. One possible explanation for the lack of observed binary RSGs is that many of them have merged. As a binary OB system evolves, the more massive star will leave the main sequence first and evolve into a RSG. If the two stars are close enough, the RSG will expand enough to engulf the secondary, causing a merger as they spin together and gain angular momentum. This event will increase the rotational velocity of the RSG by a measurable amount (> 5 km/s) and lead to unique abundances and physical properties. We've recently observed ~80 Galactic RSGs with EXPRES, a high-resolution spectrograph on the Lowell Discovery Telescope, and are in the process of using this dataset to determine the relative importance of RSG mergers before these stars end their lives as supernovae.

    This work was partially supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51516 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555.

  171. Jackman, J., Shkolnik, E., Million, C., et al., (including Richey-Yowell, T.), 2023, AAS, 55, 439.05, Bridging The UV Gap: Testing The UV Predictions of Flare Models For M Stars
    Stellar flares are explosive phenomena that release radiation across the entire electromagnetic spectrum. Their far-UV emission can dissociate atmospheric species and exacerbate atmospheric erosion. Yet, the near-UV flux may be necessary for the emergence of life on rocky planets around low-mass stars such as Proxima Centauri, LHS 3384 and TRAPPIST-1. A detailed knowledge of the UV energies and rates of flares is therefore essential for our understanding of the habitability of M dwarf systems. However, measurements of UV flare rates can require expensive campaigns with space-based instruments, limiting such measurements to individual active stars. To get around this, habitability studies instead often use UV rates based on extrapolations from white-light studies with TESS. Despite their use in contemporary habitability studies, such extrapolations are untested and as such their accuracy remains unconstrained. To this end, we are combining TESS optical photometry with archival HST and GALEX spectroscopy and photometry of M dwarfs to test the UV predictions of habitability and exoplanet atmosphere studies. We will show how white-light flare studies underestimate the UV rates of flares, how current models neglect the energy contribution from UV emission lines, and the impact our results have on our current understanding of the UV environments and habitability of terrestrial exoplanets around low-mass stars.
  172. Dorn-Wallenstein, T., Levesque, E., Davenport, J., et al., (including Neugent, K.), 2023, AAS, 55, 452.01, The Properties of Fast Yellow Pulsating Supergiants: FYPS Point the Way to Missing Red Supergiants
    Fast yellow pulsating supergiants (FYPS) are a recently-discovered class of evolved massive pulsator. As candidate post-red supergiant objects, and one of the few classes evolved massive pulsators, these objects have incredible potential to change our understanding of the structure and evolution of massive stars. Here we use data from the Transiting Exoplanet Survey Satellite (TESS) in order to examine the distribution of pulsating stars in the upper Hertzprung-Russel (HR) diagram. We find that FYPS occupy a region above logL/L5.0, corresponding to stars with initial masses 18-20 M, consistent with the most massive red supergiant progenitors of supernovae (SNe) II-P, as well as the observed properties of SNe IIb progenitors. This threshold is in agreement with the picture that FYPS are post-RSG stars. The observed properties of FYPS make them fascinating objects for future theoretical study.
  173. Omori, Y., Baxter, E., Chang, C., et al., (including Kuehn, K.), 2023, PhRvD, 107, 023529, Joint analysis of Dark Energy Survey Year 3 data and CMB lensing from SPT and Planck. I. Construction of CMB lensing maps and modeling choices
    Joint analyses of cross-correlations between measurements of galaxy positions, galaxy lensing, and lensing of the cosmic microwave background (CMB) offer powerful constraints on the large-scale structure of the Universe. In a forthcoming analysis, we will present cosmological constraints from the analysis of such cross-correlations measured using Year 3 data from the Dark Energy Survey (DES), and CMB data from the South Pole Telescope (SPT) and Planck. Here we present two key ingredients of this analysis: (1) an improved CMB lensing map in the SPT-SZ survey footprint and (2) the analysis methodology that will be used to extract cosmological information from the cross-correlation measurements. Relative to previous lensing maps made from the same CMB observations, we have implemented techniques to remove contamination from the thermal Sunyaev Zel'dovich effect, enabling the extraction of cosmological information from smaller angular scales of the cross-correlation measurements than in previous analyses with DES Year 1 data. We describe our model for the cross-correlations between these maps and DES data, and validate our modeling choices to demonstrate the robustness of our analysis. We then forecast the expected cosmological constraints from the galaxy survey-CMB lensing auto and cross-correlations. We find that the galaxy-CMB lensing and galaxy shear-CMB lensing correlations will on their own provide a constraint on S8=8{m/0.3 } at the few percent level, providing a powerful consistency check for the DES-only constraints. We explore scenarios where external priors on shear calibration are removed, finding that the joint analysis of CMB lensing cross-correlations can provide constraints on the shear calibration amplitude at the 5% to 10% level.
  174. Chang, C., Omori, Y., Baxter, E., et al., (including Kuehn, K.), 2023, PhRvD, 107, 023530, Joint analysis of Dark Energy Survey Year 3 data and CMB lensing from SPT and P l a n c k . II. Cross-correlation measurements and cosmological constraints
    Cross-correlations of galaxy positions and galaxy shears with maps of gravitational lensing of the cosmic microwave background (CMB) are sensitive to the distribution of large-scale structure in the Universe. Such cross-correlations are also expected to be immune to some of the systematic effects that complicate correlation measurements internal to galaxy surveys. We present measurements and modeling of the cross-correlations between galaxy positions and galaxy lensing measured in the first three years of data from the Dark Energy Survey with CMB lensing maps derived from a combination of data from the 2500 deg2 SPT-SZ survey conducted with the South Pole Telescope and full-sky data from the Planck satellite. The CMB lensing maps used in this analysis have been constructed in a way that minimizes biases from the thermal Sunyaev Zel'dovich effect, making them well suited for cross-correlation studies. The total signal-to-noise of the cross-correlation measurements is 23.9 (25.7) when using a choice of angular scales optimized for a linear (nonlinear) galaxy bias model. We use the cross-correlation measurements to obtain constraints on cosmological parameters. For our fiducial galaxy sample, which consist of four bins of magnitude-selected galaxies, we find constraints of m=0.272-0.052+0.032 and S88{m/0.3 }=0.736-0.028+0.032 (m=0.245-0.044+0.026 and S8=0.734-0.028+0.035 ) when assuming linear (nonlinear) galaxy bias in our modeling. Considering only the cross-correlation of galaxy shear with CMB lensing, we find m=0.270-0.061+0.043 and S8=0.740-0.029+0.034 . Our constraints on S8 are consistent with recent cosmic shear measurements, but lower than the values preferred by primary CMB measurements from Planck.
  175. Abbott, T., Aguena, M., Alarcon, A., et al., (including Kuehn, K.), 2023, PhRvD, 107, 023531, Joint analysis of Dark Energy Survey Year 3 data and CMB lensing from SPT and Planck. III. Combined cosmological constraints
    We present cosmological constraints from the analysis of two-point correlation functions between galaxy positions and galaxy lensing measured in Dark Energy Survey (DES) Year 3 data and measurements of cosmic microwave background (CMB) lensing from the South Pole Telescope (SPT) and Planck. When jointly analyzing the DES-only two-point functions and the DES cross-correlations with SPT +P l a n c k CMB lensing, we find m=0.344 0.030 and S88(m/0.3 )0.5=0.773 0.016 , assuming CDM . When additionally combining with measurements of the CMB lensing autospectrum, we find m=0.306-0.021+0.018 and S8=0.792 0.012 . The high signal-to-noise of the CMB lensing cross-correlations enables several powerful consistency tests of these results, including comparisons with constraints derived from cross-correlations only, and comparisons designed to test the robustness of the galaxy lensing and clustering measurements from DES. Applying these tests to our measurements, we find no evidence of significant biases in the baseline cosmological constraints from the DES-only analyses or from the joint analyses with CMB lensing cross-correlations. However, the CMB lensing cross-correlations suggest possible problems with the correlation function measurements using alternative lens galaxy samples, in particular the REDMAGIC galaxies and high-redshift MAGLIM galaxies, consistent with the findings of previous studies. We use the CMB lensing cross-correlations to identify directions for further investigating these problems.
  176. O'Grady, A., Drout, M., Gaensler, B., et al., (including Neugent, K.), 2023, ApJ, 943, 18, Cool, Luminous, and Highly Variable Stars in the Magellanic Clouds. II. Spectroscopic and Environmental Analysis of Thorne-Zytkow Object and Super-AGB Star Candidates
    In previous work, we identified a population of 38 cool and luminous variable stars in the Magellanic Clouds and examined 11 in detail in order to classify them as either Thorne-Zytkow objects (TZOs; red supergiants with a neutron star cores) or super-asymptotic giant branch (sAGB) stars (the most massive stars that will not undergo core collapse). This population includes HV 2112, a peculiar star previously considered in other works to be either a TZO or high-mass asymptotic giant branch (AGB) star. Here we continue this investigation, using the kinematic and radio environments and local star formation history of these stars to place constraints on the age of the progenitor systems and the presence of past supernovae. These stars are not associated with regions of recent star formation, and we find no evidence of past supernovae at their locations. Finally, we also assess the presence of heavy elements and lithium in their spectra compared to red supergiants. We find strong absorption in Li and s-process elements compared to RSGs in most of the sample, consistent with sAGB nucleosynthesis, while HV 2112 shows additional strong lines associated with TZO nucleosynthesis. Coupled with our previous mass estimates, the results are consistent with the stars being massive (~4-6.5 M ) or sAGB (~6.5-12 M ) stars in the thermally pulsing phase, providing crucial observations of the transition between low- and high-mass stellar populations. HV 2112 is more ambiguous; it could either be a maximally massive sAGB star, or a TZO if the minimum mass for stability extends down to 13 M .
  177. Morgan, R., Nord, B., Bechtol, K., et al., (including Kuehn, K.), 2023, ApJ, 943, 19, DeepZipper. II. Searching for Lensed Supernovae in Dark Energy Survey Data with Deep Learning
    Gravitationally lensed supernovae (LSNe) are important probes of cosmic expansion, but they remain rare and difficult to find. Current cosmic surveys likely contain 5-10 LSNe in total while next-generation experiments are expected to contain several hundred to a few thousand of these systems. We search for these systems in observed Dark Energy Survey (DES) five year SN fields-10 3 sq. deg. regions of sky imaged in the griz bands approximately every six nights over five years. To perform the search, we utilize the DeepZipper approach: a multi-branch deep learning architecture trained on image-level simulations of LSNe that simultaneously learns spatial and temporal relationships from time series of images. We find that our method obtains an LSN recall of 61.13% and a false-positive rate of 0.02% on the DES SN field data. DeepZipper selected 2245 candidates from a magnitude-limited (m i < 22.5) catalog of 3,459,186 systems. We employ human visual inspection to review systems selected by the network and find three candidate LSNe in the DES SN fields.
  178. Lopez-Valdivia, R., Mace, G., Han, E., et al., (including Prato, L., Llama, J.), 2023, ApJ, 943, 49, The IGRINS YSO Survey. III. Stellar Parameters of Pre-main-sequence Stars in Ophiuchus and Upper Scorpius
    We used the Immersion GRating Infrared Spectrometer (IGRINS) to determine fundamental parameters for 61 K- and M-type young stellar objects (YSOs) located in the Ophiuchus and Upper Scorpius star-forming regions. We employed synthetic spectra and a Markov chain Monte Carlo approach to fit specific K-band spectral regions and determine the photospheric temperature (T), surface gravity ( $\mathrm{log}g$ ), magnetic field strength (B), projected rotational velocity ( $v\sin i$ ), and K-band veiling (r K ). We determined B for ~46% of our sample. Stellar parameters were compared to the results from Taurus-Auriga and the TW Hydrae association presented in Paper I of this series. We classified all the YSOs in the IGRINS survey with infrared spectral indices from Two Micron All Sky Survey and Wide-field Infrared Survey Explorer photometry between 2 and 24 m. We found that Class II YSOs typically have lower $\mathrm{log}g$ and $v\sin i$ , similar B, and higher K-band veiling than their Class III counterparts. Additionally, we determined the stellar parameters for a sample of K and M field stars also observed with IGRINS. We have identified intrinsic similarities and differences at different evolutionary stages with our homogeneous determination of stellar parameters in the IGRINS YSO survey. Considering $\mathrm{log}g$ as a proxy for age, we found that the Ophiuchus and Taurus samples have a similar age. We also find that Upper Scorpius and TWA YSOs have similar ages, and are more evolved than Ophiuchus/Taurus YSOs.
  179. Massey, P., Neugent, K., Ekstrom, S., et al., 2023, ApJ, 942, 69, The Time-averaged Mass-loss Rates of Red Supergiants as Revealed by Their Luminosity Functions in M31 and M33
    Mass loss in red supergiants (RSGs) is generally recognized to be episodic, but mass-loss prescriptions fail to reflect this. Evolutionary models show that the total amount of mass lost in this phase determines if these stars evolve to warmer temperatures before undergoing core collapse. The current Geneva evolutionary models mimic episodic mass loss by enhancing the quiescent prescription rates whenever the star's outer layers exceed the Eddington luminosity by a large factor. This results in a 20 M model undergoing 10 more mass loss than it would otherwise, but has little effect on models of lower mass. We can test the validity of this approach observationally by measuring the proportion of high-luminosity RSGs to that predicted by the models. To do this, we use our recent luminosity-limited census of RSGs in M31 and M33, making modest improvements to membership, and adopting extinctions based on the recent panchromatic M31 and M33 Hubble surveys. We then compare the proportions of the highest luminosity RSGs found to that predicted by published Geneva models, as well as to a special set of models computed without the enhanced rates. We find good agreement with the models which include the supra-Eddington enhanced mass loss. The models with lower mass-loss rates predict a larger fraction of high-luminosity RSGs than observed, and thus can be ruled out. We also use these improved data to confirm that the upper luminosity limit of RSGs is $\mathrm{log}L/{L}_{\odot }\sim 5.4$ , regardless of metallicity, using our improved data on M31 and M33 plus previous results on the Magellanic Clouds.
  180. Margon, B., Morrell, N., Massey, P., et al., (including Neugent, K.), 2023, ApJ, 942, 85, A Survey for C II Emission-line Stars in the Large Magellanic Cloud. II. Final Results and the Origin of C II Emission in [WC] Spectra
    We present the final results of an imaging and spectroscopic search for stars in the Large Magellanic Cloud (LMC) with C II 7231, 7236 emission lines. The goal is to identify and study [WC11] stars, the coolest of the low-mass Wolf-Rayet sequence, and a subset of central stars of planetary nebulae where the C II lines are known to be especially prominent. A recent serendipitous discovery of an LMC [WC11] raised the possibility that these objects, although difficult to identify, might in fact be more common than previously believed. Several new members of this rare class have been found in this survey. It now seems clear, however, that a significant number of these stars are not hiding among the general [WC] population. We point out that the C II doublet intensity ratio observed in our spectra proves to neatly divide the objects into two distinct groups, with the C II emission likely originating from either the stellar wind or a surrounding nebula. The physics of the C II emission mechanism correctly explains this bifurcation. Spectral subtypes are suggested for most of the objects. The numerous spectroscopic clues now available for these objects should facilitate future detailed modeling.
  181. Meldorf, C., Palmese, A., Brout, D., et al., (including Kuehn, K.), 2023, MNRAS, 518, 1985, The Dark Energy Survey Supernova Program results: type Ia supernova brightness correlates with host galaxy dust
    Cosmological analyses with type Ia supernovae (SNe Ia) often assume a single empirical relation between colour and luminosity () and do not account for varying host-galaxy dust properties. However, from studies of dust in large samples of galaxies, it is known that dust attenuation can vary significantly. Here, we take advantage of state-of-the-art modelling of galaxy properties to characterize dust parameters (dust attenuation AV, and a parameter describing the dust law slope RV) for 1100 Dark Energy Survey (DES) SN host galaxies. Utilizing optical and infrared data of the hosts alone, we find three key aspects of host dust that impact SN cosmology: (1) there exists a large range (~1-6) of host RV; (2) high-stellar mass hosts have RV on average ~0.7 lower than that of low-mass hosts; (3) for a subsample of 81 spectroscopically classified SNe there is a significant (>3) correlation between the Hubble diagram residuals of red SNe Ia and the host RV that when corrected for reduces scatter by $\sim 13{{\ \rm per\ cent}}$ and the significance of the 'mass step' to ~1. These represent independent confirmations of recent predictions based on dust that attempted to explain the puzzling 'mass step' and intrinsic scatter (int) in SN Ia analyses.
  182. Cheng, T., Dominguez Sanchez, H., Vega-Ferrero, J., et al., (including Kuehn, K.), 2023, MNRAS, 518, 2794, Lessons learned from the two largest Galaxy morphological classification catalogues built by convolutional neural networks
    We compare the two largest galaxy morphology catalogues, which separate early- and late-type galaxies at intermediate redshift. The two catalogues were built by applying supervised deep learning (convolutional neural networks, CNNs) to the Dark Energy Survey data down to a magnitude limit of ~21 mag. The methodologies used for the construction of the catalogues include differences such as the cutout sizes, the labels used for training, and the input to the CNN - monochromatic images versus gri-band normalized images. In addition, one catalogue is trained using bright galaxies observed with DES (i < 18), while the other is trained with bright galaxies (r < 17.5) and 'emulated' galaxies up to r-band magnitude 22.5. Despite the different approaches, the agreement between the two catalogues is excellent up to i < 19, demonstrating that CNN predictions are reliable for samples at least one magnitude fainter than the training sample limit. It also shows that morphological classifications based on monochromatic images are comparable to those based on gri-band images, at least in the bright regime. At fainter magnitudes, i > 19, the overall agreement is good (~95 per cent), but is mostly driven by the large spiral fraction in the two catalogues. In contrast, the agreement within the elliptical population is not as good, especially at faint magnitudes. By studying the mismatched cases, we are able to identify lenticular galaxies (at least up to i < 19), which are difficult to distinguish using standard classification approaches. The synergy of both catalogues provides an unique opportunity to select a population of unusual galaxies.
  183. Vincenzi, M., Sullivan, M., Moller, A., et al., (including Kuehn, K.), 2023, MNRAS, 518, 1106, The Dark Energy Survey supernova program: cosmological biases from supernova photometric classification
    Cosmological analyses of samples of photometrically identified type Ia supernovae (SNe Ia) depend on understanding the effects of 'contamination' from core-collapse and peculiar SN Ia events. We employ a rigorous analysis using the photometric classifier SuperNNova on state-of-the-art simulations of SN samples to determine cosmological biases due to such 'non-Ia' contamination in the Dark Energy Survey (DES) 5-yr SN sample. Depending on the non-Ia SN models used in the SuperNNova training and testing samples, contamination ranges from 0.8 to 3.5 per cent, with a classification efficiency of 97.7-99.5 per cent. Using the Bayesian Estimation Applied to Multiple Species (BEAMS) framework and its extension BBC ('BEAMS with Bias Correction'), we produce a redshift-binned Hubble diagram marginalized over contamination and corrected for selection effects, and use it to constrain the dark energy equation-of-state, w. Assuming a flat universe with Gaussian M prior of 0.311 0.010, we show that biases on w are <0.008 when using SuperNNova, with systematic uncertainties associated with contamination around 10 per cent of the statistical uncertainty on w for the DES-SN sample. An alternative approach of discarding contaminants using outlier rejection techniques (e.g. Chauvenet's criterion) in place of SuperNNova leads to biases on w that are larger but still modest (0.015-0.03). Finally, we measure biases due to contamination on w0 and wa (assuming a flat universe), and find these to be <0.009 in w0 and <0.108 in wa, 5 to 10 times smaller than the statistical uncertainties for the DES-SN sample.
  184. Schmidt, T., Treu, T., Birrer, S., et al., (including Kuehn, K.), 2023, MNRAS, 518, 1260, STRIDES: automated uniform models for 30 quadruply imaged quasars
    Gravitational time delays provide a powerful one-step measurement of H0, independent of all other probes. One key ingredient in time-delay cosmography are high-accuracy lens models. Those are currently expensive to obtain, both, in terms of computing and investigator time (105-106 CPU hours and ~0.5-1 yr, respectively). Major improvements in modelling speed are therefore necessary to exploit the large number of lenses that are forecast to be discovered over the current decade. In order to bypass this roadblock, we develop an automated modelling pipeline and apply it to a sample of 31 lens systems, observed by the Hubble Space Telescope in multiple bands. Our automated pipeline can derive models for 30/31 lenses with few hours of human time and <100 CPU hours of computing time for a typical system. For each lens, we provide measurements of key parameters and predictions of magnification as well as time delays for the multiple images. We characterize the cosmography-readiness of our models using the stability of differences in the Fermat potential (proportional to time delay) with respect to modelling choices. We find that for 10/30 lenses, our models are cosmography or nearly cosmography grade (<3 per cent and 3-5 per cent variations). For 6/30 lenses, the models are close to cosmography grade (5-10 per cent). These results utilize informative priors and will need to be confirmed by further analysis. However, they are also likely to improve by extending the pipeline modelling sequence and options. In conclusion, we show that uniform cosmography grade modelling of large strong lens samples is within reach.
  185. Amon, A., Robertson, N., Miyatake, H., et al., (including Kuehn, K.), 2023, MNRAS, 518, 477, Consistent lensing and clustering in a low-S8 Universe with BOSS, DES Year 3, HSC Year 1, and KiDS-1000
    We evaluate the consistency between lensing and clustering based on measurements from Baryon Oscillation Spectroscopic Survey combined with galaxy-galaxy lensing from Dark Energy Survey (DES) Year 3, Hyper Suprime-Cam Subaru Strategic Program (HSC) Year 1, and Kilo-Degree Survey (KiDS)-1000. We find good agreement between these lensing data sets. We model the observations using the DARK EMULATOR and fit the data at two fixed cosmologies: Planck (S8 = 0.83), and a Lensing cosmology (S8 = 0.76). For a joint analysis limited to large scales, we find that both cosmologies provide an acceptable fit to the data. Full utilization of the higher signal-to-noise small-scale measurements is hindered by uncertainty in the impact of baryon feedback and assembly bias, which we account for with a reasoned theoretical error budget. We incorporate a systematic inconsistency parameter for each redshift bin, A, that decouples the lensing and clustering. With a wide range of scales, we find different results for the consistency between the two cosmologies. Limiting the analysis to the bins for which the impact of the lens sample selection is expected to be minimal, for the Lensing cosmology, the measurements are consistent with A = 1; A = 0.91 0.04 (A = 0.97 0.06) using DES+KiDS (HSC). For the Planck case, we find a discrepancy: A = 0.79 0.03 (A = 0.84 0.05) using DES+KiDS (HSC). We demonstrate that a kinematic Sunyaev-Zeldovich-based estimate for baryonic effects alleviates some of the discrepancy in the Planck cosmology. This analysis demonstrates the statistical power of small-scale measurements; however, caution is still warranted given modelling uncertainties and foreground sample selection effects.
  186. Fitzmaurice, E., Martin, D., Rodriguez Martinez, R., et al., (including Stephan, A., Kunovac, V.), 2023, MNRAS, 518, 636, Spectroscopy of TOI-1259B - an unpolluted white dwarf companion to an inflated warm Saturn
    TOI-1259 consists of a transiting exoplanet orbiting a main-sequence star, with a bound outer white dwarf (WDs) companion. Less than a dozen systems with this architecture are known. We conduct follow-up spectroscopy on the WD TOI-1259B using the Large Binocular Telescope to better characterize it. We observe only strong hydrogen lines, making TOI-1259B a DA WD. We see no evidence of heavy element pollution, which would have been evidence of planetary material around the WD. Such pollution is seen in $\sim 25{-}50{{\ \rm per\ cent}}$ of WDs, but it is unknown if this rate is higher or lower in TOI-1259-like systems that contain a known planet. Our spectroscopy permits an improved WD age measurement of $4.05^{+1.00}_{-0.42}$ Gyr, which matches gyrochronology of the main-sequence star. This is the first of an expanded sample of similar binaries that will allow us to calibrate these dating methods and provide a new perspective on planets in binaries.
  187. del Ser, D., Fors, O., del Alcazar, M., et al., (including van Belle, G., Clark, C.), 2023, MNRAS, 518, 669, TFAW survey II: six newly validated planets and 13 planet candidates from K2
    Searching for Earth-sized planets in data from Kepler's extended mission (K2) is a niche that still remains to be fully exploited. The TFAW survey is an ongoing project that aims to re-analyse all light curves in K2 C1-C8 and C12-C18 campaigns with a wavelet-based detrending and denoising method, and the period search algorithm TLS to search for new transit candidates not detected in previous works. We have analysed a first subset of 24 candidate planetary systems around relatively faint host stars (10.9 < Kp < 15.4) to allow for follow-up speckle imaging observations. Using vespa and TRICERATOPS, we statistically validate six candidates orbiting four unique host stars by obtaining false-positive probabilities smaller than 1 per cent with both methods. We also present 13 vetted planet candidates that might benefit from other, more precise follow-up observations. All of these planets are sub-Neptune-sized with two validated planets and three candidates with sub-Earth sizes, and have orbital periods between 0.81 and 23.98 d. Some interesting systems include two ultra-short-period planets, three multiplanetary systems, three sub-Neptunes that appear to be within the small planet Radius Gap, and two validated and one candidate sub-Earths (EPIC 210706310.01, K2-411 b, and K2-413 b) orbiting metal-poor stars.
  188. Lilleengen, S., Petersen, M., Erkal, D., et al., (including Kuehn, K.), 2023, MNRAS, 518, 774, The effect of the deforming dark matter haloes of the Milky Way and the Large Magellanic Cloud on the Orphan-Chenab stream
    It has recently been shown that the Large Magellanic Cloud (LMC) has a substantial effect on the Milky Way's stellar halo and stellar streams. Here, we explore how deformations of the Milky Way and LMC's dark matter haloes affect stellar streams, and whether these effects are observable. In particular, we focus on the Orphan-Chenab (OC) stream which passes particularly close to the LMC and spans a large portion of the Milky Way's halo. We represent the Milky Way-LMC system using basis function expansions that capture their evolution in an N-body simulation. We present the properties of this system, such as the evolution of the densities and force fields of each galaxy. The OC stream is evolved in this time-dependent, deforming potential, and we investigate the effects of the various moments of the Milky Way and the LMC. We find that the simulated OC stream is strongly influenced by the deformations of both the Milky Way and the LMC and that this effect is much larger than current observational errors. In particular, the Milky Way dipole has the biggest impact on the stream, followed by the evolution of the LMC's monopole, and the LMC's quadrupole. Detecting these effects would confirm a key prediction of collisionless, cold dark matter, and would be a powerful test of alternative dark matter and alternative gravity models.
  189. Cook, J., Protopapa, S., Dalle Ore, C., et al., (including Grundy, W.), 2023, Icar, 389, 115242, Analysis of Charon's spectrum at 2.21- m from New Horizons/LEISA and Earth-based observations
    We examine the 2.21- m band from 19 disk-integrated Charon spectra measured by New Horizons/LEISA in the week leading up to its closest encounter with the Pluto system. These observations cover one Charon rotation period. Additionally, we analyze Charon's 2.21- m band from 22 Earth-based spectra obtained over the last two decades. We measure the equivalent width of the 2.21- m band from all observations and study it as a function of sub-observer longitude. We find no significant variation in the 2.21- m band as Charon rotates. Compared to the same band seen on Nix and Hydra, Charon's 2.21- m band is several times weaker. We attribute the 2.21- m band to NH4Cl based on the appearance of a weaker band at 2.24- m . Furthermore, we see two never-before-reported absorption features in Charon's spectrum at 1.60 and 1.63- m , which may also be due to NH4Cl. If NH3-H2O-ice mixtures are present on Charon, they must be a small fraction of the disk-average composition to be consistent with the spectrum at 1.99- m .
  190. DeMeo, F., Marsset, M., Polishook, D., et al., (including Burt, B., Moskovitz, N.), 2023, Icar, 389, 115264, Isolating the mechanisms for asteroid surface refreshing
    Evidence is seen for young, fresh surfaces among Near-Earth and Main-Belt asteroids even though space-weathering timescales are shorter than the age of the surfaces. A number of mechanisms have been proposed to refresh asteroid surfaces on short timescales, such as planetary encounters, YORP spinup, thermal degradation, and collisions. Additionally, other factors such as grain size effects have been proposed to explain the existence of these "fresh-looking" spectra. To investigate the role each of these mechanisms may play, we collected a sample of visible and near-infrared spectra of 477 near-Earth and Mars Crosser asteroids with similar sizes and compositions - all with absolute magnitude H > 16 and within the S-complex and having olivine to pyroxene (ol/(ol+opx)) ratios >0.65. We taxonomically classify these objects in the Q (fresh) and S (weathered) classes. We find four trends in the Q/S ratio: (1) previous work demonstrated the Q/S ratio increases at smaller sizes down to H 16, but we find a sharp increase near H 19 after which the ratio decreases monotonically. (2) in agreement with many previous studies, the Q/S ratio increases with decreasing perihelion distance, and we find it is non-zero for larger perihelia >1.2AU, (3) as a new finding our work reveals the Q/S ratio has a sharp, significant peak near 5 orbital inclination, and (4) we confirm previous findings that the Q/S ratio is higher for objects that have the possibility of encounter with Earth and Venus versus those that do not, however this finding cannot be distinguished from the perihelion trend. No single resurfacing mechanism can explain all of these trends, so multiple mechanisms are required. YORP spin-up scales with size, thermal degradation is dependent on perihelion, planetary encounters trend with inclination, perihelion and MOID, noting that asteroid-asteroid collisions are also dependent on inclination. It is likely that a combination of all four resurfacing mechanisms are needed to account for all observational trends.
  191. Elmegreen, B., Hunter, D., Martinez, Z., et al., (including Archer, H.), 2023, IAUS, 373, 93, A search for correlations between turbulence and star formation in LITTLE THINGS and THINGS galaxies
    Azimuthal variations in HI velocity dispersion do not correlate with variations in the star formation rate per unit area, SFR/A, suggesting that local star formation does not increase HI turbulence significantly. These variations are determined for each pixel in HI and FUV maps of THINGS and LITTLE THINGS galaxies by subtracting the average radial profiles from the measured quantities. The kinetic energy density and HI surface density increase slightly with SFR/A, suggesting that feedback goes into pushing the local dense gas around without increasing the velocity dispersion. We suggest that star formation feedback does not promote large-scale stability against gravitational forces through turbulence regulation, and that gravitational energy from recurrent instabilities drives turbulence on galactic scales.
  192. 191 publications and 1074 citations in 2023.

191 publications and 1074 citations total.