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Recent research involving Lowell Observatory staff
(All publications with publication dates in June 2025)

This is a work ever in progress.

(Pulled from ADS* by sel on 2025-07-07)

*We are grateful for all the effort that went into making The SAO/NASA Astrophysics Data System (ADS) possible. The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A and can be found at: https://ui.adsabs.harvard.edu/

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    2025

  1. Choukroun, A., Marciniak, A., Durech, J., Pera, J., Ogoza, W., Szakats, R., Molnar, L., Pal, A., Monteiro, F., Mieczkowska, I., Beisker, W., Agnetti, D., Anderson, C., Andersson, S., Antuszewicz, D., Arcoverde, P., Aubry, R., Bacci, P., Bacci, R., Baruffetti, P., Benedyktowicz, L., Bertini, M., Bazewicz, D., Boninsegna, R., Bora, Z., Borkowski, M., Bredner, E., Broughton, J., Butkiewicz-Bak, M., Carlson, N., Casalnuovo, G., Casarramona, F., Choi, Y., Cikota, S., Collins, M., Cseh, B., Csornyei, G., De Groot, H., Delincak, P., Denyer, P., Dequinze, R., Dogramatzidis, M., Drozdz, M., Duffard, R., Eisfeldt, D., Eleftheriou, M., Ellington, C., Fauvaud, S., Fauvaud, M., Ferrais, M., Filipek, M., Fini, P., Frits, M., Gahrken, B., Galli, G., Gault, D., Geier, S., Gimple, B., Golonka, J., Grazzini, L., Grice, J., Guhl, K., Hanna, W., Harman, M., Hasubick, W., Haymes, T., Herald, D., Higgins, D., Hirsch, R., Horbowicz, J., Horti-David, A., Ignacz, B., Jehin, E., Jones, A., Jones, R., Dunham, D., Kalup, C., Kaminski, K., Kaminska, M., Kankiewicz, P., Kaplan, M., Karagiannidis, A., Kattentidt, B., Kidd, S., Kirpluk, B., Kim, D., Kim, M., Konstanciak, I., Krannich, G., Kretlow, M., Kubanek, J., Kudak, V., Kulczak, P., Lecossois, M., Leiva, R., Libert, M., Licandro, J., Lindner, P., Liu, R., Liu, Y., Lyzenga, G., Maestripieri, M., Malagon, C., Maley, P., Manna, A., Messner, S., Michniewicz, O., Miftah, M., Mizutani, M., Morales, N., Murawiecka, M., Nadolny, J., Nemoto, T., Newman, J., Nikitin, V., Nosal, P., Nosworthy, P., O'Connell, M., Oey, J., Ortiz-Ochoa, A., Ossola, A., Oszkiewicz, D., Pakstiene, E., Pawowski, M., Perig, V., Petrescu, E., Pilcher, F., Podlewska-Gaca, E., Polacek, M., Polak, J., Polakis, T., Polinska, M., Popowicz, A., Reddy, V., Rives, J., Rottenborn, M., Ruocco, N., Rutkowski, A., Saci, K., Santana-Ros, T., Sarneczky, K., Schreurs, O., Sempronio, V., Skiff, B., Skrzypek, J., Smith, D., Sobkowiak, K., Sonbas, E., Sposetti, S., Stewart, C., Stewart, W., Swift, T., Szkudlarek, M., Szyszka, K., Takacs, N., Tychoniec, .., Uno, M., Urakawa, S., Vida, K., Weber, C., Wunsche, N., Yamamura, H., Yoshihara, H., Zawilski, M., Zeleny, P., Zoa, S., Zejmo, M., Zukowski, K., 2025, A&A, 698, A298, Asteroid sizes determined with thermophysical model and stellar occultations
    Context. The sizes of many asteroids, especially slowly rotating, low-amplitude targets, remain poorly constrained due to selection effects. These biases limit the availability of high-quality data, leaving size estimates reliant on spherical shape assumptions. Such approximations introduce significant uncertainties propagating, for example, into density determinations or thermophysical and compositional studies, affecting our understanding of asteroid properties. Aims. This work targets poorly studied main-belt asteroids, for most of which no shape models were previously available. Using only high-quality, dense light curves, thermal infrared observations (systematically including WISE data), and stellar occultations, we aimed to produce reliable shape models and scale them using two independent techniques, allowing for size comparison at the end. We conducted two observing campaigns to achieve this: one to obtain dense photometric light curves and another to acquire multi-chord stellar occultations by these objects. Methods. Shape and spin models were reconstructed using light curve inversion techniques. Sizes were determined via two methods: (1) advanced thermophysical modelling using the convex inversion thermophysical model (CITPM), which optimises spin and shape models to light curve data in the visible range together with infrared data, and (2) scaling the shape models with stellar occultations. Results. We obtained precise sizes and shape models for 15 asteroids. CITPM and occultation-derived sizes agree within 5% for most cases, demonstrating the reliability of the modelling approach. Larger discrepancies are usually linked to incomplete occultation chord coverage. The study also provides insights into surface properties, including albedo, surface roughness and thermal inertia. Conclusions. The use of high-quality data, coupled with an advanced TPM that uses both thermal and visible data while allowing the shape model to be adjusted according to both types of data, enabled us to determine sizes with precision comparable to those derived from multichord stellar occultations. We resolved substantial inconsistencies in previous size determinations for target asteroids, providing good input for future studies on asteroid densities and surface properties.
  2. Rector, T., Prato, L., Kerr, R., 2025, AAS, 246, 212.04, Exploring New Paradigms in Star Formation with Gaia Kinematics and Herbig-Haro Objects
    How does our Galaxy form stars? Some regions show rapid star formation that quickly builds star clusters, while others show much more gradual formation. What factors determine these different star formation rates? Gaia programs such as SPYGLASS have revealed an incredible diversity of young (< 50 Myr) stellar populations with a wide range of scales and star formation histories that show several compelling new patterns. In the Circinus Complex and several other populations, multi-generational star formation sequences have been discovered that can span tens of millions of years. Herbig-Haro (HH) objects embedded in the youngest components of these populations are a clear indicator of active star formation. Multi-band imaging surveys of HH objects thus provide a powerful means for determining the evolutionary state of the youngest areas within a complex star-forming region, and can therefore determine whether star formation within a multi-generational sequence is still underway and propagating into adjacent clouds. In our work to date we have identified over 180 new HH objects, revealing the youngest generation of star formation in the Aquila, Ophiuchus, and Circinus star-forming regions, among others. We present our latest results using Gaia and HH object surveys to characterize the star formation paradigms in the solar neighborhood.
  3. Sciamma-O'Brien, E., Cook, J., Emran, A., Dalle Ore, C., Wooden, D., Roush, T., Drant, T., Jovanovic, L., Ricketts, C., Bertrand, T., Salama, F., Grundy, W., 2025, AAS, 246, 217.05, Integrated laboratory, modeling, and observational investigations of the origins of Pluto's surface dark materials
    Pluto's flyby by the New Horizons mission unveiled a world with surprisingly diverse surface compositions and colors and an extensive haze in its N2-dominated atmosphere. The range of brown to yellow- and red-brown hues observed on Pluto's surface by the Ralph instrument indicate the presence of one or more colored components mixed in or superimposed on the ices. On Pluto, the volatile species in both solid and gaseous states are exposed to ultraviolet photons, galactic cosmic rays, and charged particles from the Sun, which can fragment and ionize them, resulting in chemical reactions. Haze particles resulting from the photolysis and radiolysis of gaseous N2, CH4, and CO in Pluto's atmosphere are expected to settle and accumulate onto the surface and could thus darken the surface and contaminate the ices. Here we present the results of an interdisciplinary research effort combining the expertise of experimentalists, modelers, and observers to assess the contribution of Pluto's atmospheric haze particles (in pure form, layers of different compositions, or as contaminants in N2 and CH4 ices) to the dark materials present on various regions across Pluto's surface, in order to reach a better understanding of the processes that result in the surprising diversity of colors and spectral features observed by New Horizons. We focused our study on three main regions that are covered with dark materials of very different colors and spectral features: Lowell Regio (yellow), Sputnik Planitia (pale orange), and Cthulhu (red). We first produced new laboratory Pluto aerosol analogs with the NASA Ames COsmic SImulation Chamber (COSmIC) from various gas mixtures representative of different seasons and epochs, in order to assess the climatic context and epochs of formation for the dark materials observed in each region. We then determined their complex refractive indices from reflectance and transmission measurements performed from 0.4 to 2.5 m with the NASA Ames Optical Constants Facility (OCF). In parallel we processed and conducted a statistical clustering of Pluto observations from the MVIC (Multispectral Visible Imaging Camera) and LEISA (Linear Etalon Imaging Spectral Array) instruments. Finally, we compared the resulting clustered spectra with synthetic spectra obtained with a Hapke spectral reflectance model using the complex indices of refraction of our Pluto tholins produced in COSmIC. We will discuss the results obtained from this investigation.
  4. Breeland-Newcomb, K., Moskovitz, N., Levine, S., Wasserman, L., 2025, AAS, 246, 218.01, Quantifying Nightly Occultation Rates from a Single Telescope
    A stellar occultation occurs when an object in the solar system crosses an observer's line of sight to a star. The structure of the ingress or egress of an occultation can provide insight into the star's angular diameter and atmospheric structure, while an event's depth and duration can yield information about the occulting body's size and shape. This work aims to quantify the nightly frequency of these events from a single site, ultimately defining the parameters of a facility optimized for systematic observations of occultations. We start by cross-referencing the equatorial coordinates of stars in Gaia's DR3 catalogue with ephemerides of Main Belt asteroids in Lowell Observatory's astorb database. For simplicity, we run this analysis for a representative observer location at the geocenter. We calculate the number of events per night for a representative date in each season, finding 189 occultations/night in the spring, 244/night in the summer, 345/night in the fall, and 45/night in the winter. Extrapolation of these statistics suggests an upper limit of ~70,000 occultations observable from a single site annually. We evaluate the feasibility of observing each occultation based on the contrast in brightness between the object and the star, and by considering the signal-to-noise ratio achieved for a given event duration and stellar magnitude. For a 0.5-m telescope, we found roughly 9 events/night (~3,000 annually) with S/N values >2 (maximum of 150) and integration times ranging from 40 ms to 1.6 s. For a 1-m telescope, these scale to roughly 14 events/night (~5,000 annually) with S/N values >2 (maximum of 300) and integration times ranging from 20 ms to 1.6 s. This result shows that a single automated site could potentially observe as many Main Belt occultations per night as are now typically reported online. As LSST is expected to increase the number of known asteroids by a factor of 10, we anticipate these statistics to scale by a similar factor in the coming years.
  5. Ardila, D., Shkolnik, E., Basset, C., Bowman, J., Gamaunt, J., Gregory, D., Jacobs, D., Jensen, L., Jewell, A., Knapp, M., Kolopanis, M., Ladwig, M., Llama, J., Nikzad, S., Peacock, S., Ramiaramanantsoa, T., Scowen, P., Struebel, N., Swain, M., 2025, AAS, 246, 233.03, SPARCS and the SmallSat Revolution: A Case Study
    The Star-Planet Activity Research CubeSat (SPARCS) is a NASA-funded 6U CubeSat mission designed to monitor ultraviolet (UV) radiation from low-mass stars. These stars' relatively high-frequency and high-energy UV flares significantly affect the atmospheres of orbiting exoplanets, driving atmospheric loss and altering the conditions for habitability. SPARCS aims to capture time-resolved photometric data in the far- and near-ultraviolet simultaneously, to better characterize the flares and detect the strongest and rarest among them. In addition, SPARCS is testing innovative technology, such as -doped UV detectors with near 100% internal quantum efficiency and detector-integrated metal dielectric UV bandpass filters. SPARCS has passed pre-shipment review, and it is scheduled for launch in the Fall of 2025.

    The landscape for exoplanets has changed significantly since SPARCS was first proposed, and the mission provides an interesting case study to illuminate these changes. We discuss here the role that SmallSats play in the NASA Astrophysics portfolio, and some of the lessons we have learned in the process of designing, fabricating, and testing SPARCS. These lessons include the importance of transparent communication, the difficulties in dealing with changing contractors, the challenges for NASA-funded, university-led missions, the importance of budget margins, and the crucil role that peer-learning with other small missions can have.

  6. Prato, L., 2025, AAS, 246, 406.02, Mapping Inner Disk Structure in the Closest Young Binaries with He I 10830A Lines
    Most young stellar objects in nearby star forming regions reside in binary and multiple systems. Although circumstellar disks in these configurations are less massive and evolve more rapidly than their single star disk counterparts, many nevertheless persist for millions of years and have been shown to host young planets. Disks around the stars in the closest resolved young binaries, with separations of a few to tens of AU, are truncated at outer radii of ~1/3 the binary semi-major axis. Component-resolved, high-resolution spectra of the He I 10830A line show evidence for accretion plus winds from the stars and disks, launched over a range of radii and betraying the inner disk structure and activity. I will present results from recent He I 10830A observations, complemented with high-angular resolution data from ALMA and other facilities, for several binary systems in the Taurus region.
  7. Tusay, N., Kesseli, A., Polanski, A., Householder, A., 2025, AAS, 246, 413.02, Observations of the Ultra-Hot Jupiter WASP-82 using ESPRESSO and KPF
    The intense irradiation that Ultra-Hot Jupiters (UHJs) experience from their host star dissociates molecular species in the planet's atmosphere, creating gaseous neutral and ionized metals, such as Fe, Mg, Ni, etc. These planets are tidally locked due to their short orbital periods, causing a large day-to-night temperature contrast. This leads to non-uniform cloud formation, strong atmospheric winds that blow from the hot dayside to the cool nightside, and a super-rotational jet in the direction of tidally locked rotation. The relatively large signals from transmission spectra of the hot, extended atmospheres of UHJs offers the best opportunity to test atmospheric circulation and dynamics models from state-of-the-art global circulation models (GCMs). The fine radial velocity spacing offered by high resolution optical spectrographs are able to resolve ~km s-1 winds in these exoplanetary atmospheres. Cross-correlation of atmospheric models can also measure relative abundances of metals, which primarily exhibit narrow absorption features in optical wavelengths.

    The preliminary results of our analysis of recent observations of WASP-82, using the ESPRESSO and KPF instruments, yield measurements of the spin-orbit angle (obliquity) of the UHJ around this F-type (6500 K) star using the Rossiter-McLaughlin technique. Retrieval frameworks of atmospheric models are being used to determine precise abundances of the dominant atomic and molecular species. Altogether, the results of this analysis will be compared against the similar WASP-76 to identify commonalities and differences in their heat circulation profiles.

  8. Thakore, B., Negro, M., Regis, M., Camera, S., Gruen, D., Fornengo, N., Roodman, A., Porredon, A., Schutt, T., Cuoco, A., Alarcon, A., Amon, A., Bechtol, K., Becker, M., Bernstein, G., Campos, A., Carnero Rosell, A., Carrasco Kind, M., Cawthon, R., Chang, C., Chen, R., Choi, A., Cordero, J., Davis, C., DeRose, J., Diehl, H., Dodelson, S., Doux, C., Drlica-Wagner, A., Eckert, K., Elvin-Poole, J., Everett, S., Ferte, A., Gatti, M., Giannini, G., Gruendl, R., Harrison, I., Hartley, W., Huff, E., Jarvis, M., Kuropatkin, N., Leget, P., MacCrann, N., McCullough, J., Myles, J., Navarro-Alsina, A., Pandey, S., Prat, J., Raveri, M., Rollins, R., Ross, A., Rykoff, E., Sanchez, C., Secco, L., Sevilla-Noarbe, I., Sheldon, E., Shin, T., Troxel, M., Tutusaus, I., Yanny, B., Yin, B., Zhang, Y., Aguena, M., Brooks, D., Carretero, J., da Costa, L., Davis, T., De Vicente, J., Desai, S., Doel, P., Flaugher, B., Frieman, J., Garcia-Bellido, J., Gaztanaga, E., Gutierrez, G., Hinton, S., Hollowood, D., Honscheid, K., James, D., Kuehn, K., Lahav, O., Lee, S., Lima, M., Marshall, J., Mena-Fernandez, J., Miquel, R., Ogando, R., Palmese, A., Pieres, A., Plazas Malagon, A., Samuroff, S., Sanchez, E., Sanchez Cid, D., Smith, M., Suchyta, E., Tarle, G., Vikram, V., Walker, A., Weaverdyck, N., 2025, JCAP, 2025, 037, High-significance detection of correlation between the unresolved gamma-ray background and the large-scale cosmic structure
    Our understanding of the -ray sky has improved dramatically in the past decade, however, the unresolved -ray background (UGRB) still has a potential wealth of information about the faintest -ray sources pervading the Universe. Statistical cross-correlations with tracers of cosmic structure can indirectly identify the populations that most characterize the -ray background. In this study, we analyze the angular correlation between the -ray background and the matter distribution in the Universe as traced by gravitational lensing, leveraging more than a decade of observations from the Fermi-Large Area Telescope (LAT) and 3 years of data from the Dark Energy Survey (DES). We detect a correlation at signal-to-noise ratio of 8.9. Most of the statistical significance comes from large scales, demonstrating, for the first time, that a substantial portion of the UGRB aligns with the mass clustering of the Universe as traced by weak lensing. Blazars provide a plausible explanation for this signal, especially if those contributing to the correlation reside in halos of large mass ( 1014 M ) and account for approximately 3040% of the UGRB above 10 GeV. Additionally, we observe a preference for a curved -ray energy spectrum, with a log-parabolic shape being favored over a power-law. We also discuss the possibility of modifications to the blazar model and the inclusion of additional -ray sources, such as star-forming galaxies, misalinged active galactic nuclei, or particle dark matter.
  9. Minker, K., Carry, B., Vachier, F., Scheirich, P., Pravec, P., Muller, T., Moor, A., Arcidiacono, C., Conrad, A., Veillet, C., Jacobson, S., Marsset, M., Merline, W., Tamblyn, P., Brown, M., Pray, D., Montaigut, R., Leroy, A., Gillier, C., Kusnirak, P., Hornoch, K., Husarik, M., Benishek, V., Cooney, W., Gross, J., Terrell, D., Jehin, E., Vilagi, J., Gajdos, S., Chiorny, V., Christmann, B., Brinsfield, J., Dumas, C., Enke, B., Durda, D., Christou, J., Grundy, W., Close, L., Porter, S., 2025, A&A, 698, A136, Orbits of very distant asteroid satellites
    Context. The very wide binary asteroid (VWBA) population is a small subset of the population of known binary and multiple asteroids made of systems with very widely orbiting satellites and long orbital periods, on the order of tens to hundreds of days. The origin of these systems is debatable, and most members of this population are poorly characterized. Aims. We aim to develop orbital solutions for some members of the VWBA population, allowing us to constrain possible formation pathways for this unusual population. Methods. We compiled all available high-angular-resolution imaging archival data of VWBA systems from large ground- and space-based telescopes. We measured the astrometric positions of the satellite relative to the primary at each epoch and analyzed the dynamics of the satellites using the Genoid genetic algorithm. Additionally, we used a NEATM thermal model to estimate the diameters of two systems, and we modeled the orbit of Litva's inner satellite using photometric light curve observations. Results. We determine the effective diameters of binary systems (17246) Christophedumas and (22899) Alconrad to be 4.7 0.4 km and 5.2 0.3 km, respectively. We determine new orbital solutions for five systems, (379) Huenna, (2577) Litva, (3548) Eurybates, (4674) Pauling, and (22899) Alconrad. We find a significantly eccentric (e = 0.30) best-fit orbital solution for the outer satellite of (2577) Litva, moderately eccentric (e = 0.13) solutions for (22899) Alconrad, and a nearly circular solution for (4674) Pauling (e = 0.04). We also confirm previously reported orbital solutions for (379) Huenna and (3548) Eurybates. Conclusions. It is unlikely that BYORP expansion could be solely responsible for the formation of VWBAs, as only (4674) Pauling matches the necessary requirements for active BYORP expansion. It is possible that the satellites of these systems were formed through YORP spin-up and then later scattered onto very wide orbits. Additionally, we find that some members of the population are unlikely to have formed satellites through YORP spin-up, and a collisional formation history is favored. In particular, this applies to VWBAs within large dynamical families, such as (22899) Alconrad and (2577) Litva, or large VWBA systems such as (379) Huenna and NASA's Lucy mission target (3548) Eurybates.
  10. Howard, A., Sinukoff, E., Blunt, S., Petigura, E., Crossfield, I., Isaacson, H., Kosiarek, M., Rubenzahl, R., Brewer, J., Fulton, B., Dressing, C., Hirsch, L., Knutson, H., Livingston, J., Mills, S., Roy, A., Weiss, L., Benneke, B., Ciardi, D., Christiansen, J., Cochran, W., Crepp, J., Gonzales, E., Hansen, B., Hardegree-Ullman, K., Howell, S., Lepine, S., Martinez, A., Rogers, L., Schlieder, J., Werner, M., Polanski, A., Angelo, I., Beard, C., Behmard, A., Bouma, L., Brinkman, C., Chontos, A., Dai, F., Dalba, P., Giacalone, S., Grunblatt, S., Hill, M., Kane, S., Lubin, J., Mayo, A., Mocnik, T., Murphy, J., Rice, M., Rosenthal, L., Tyler, D., Van Zandt, J., Yee, S., 2025, ApJS, 278, 52, Planet Masses, Radii, and Orbits from NASA's K2 Mission
    We report the masses, sizes, and orbital properties of 86 planets orbiting 55 stars observed by NASA's K2 Mission with follow-up Doppler measurements by the HIRES spectrometer at the W. M. Keck Observatory and the Automated Planet Finder at Lick Observatory. Eighty-one of the planets were discovered from their transits in the K2 photometry, while five were found based on subsequent Doppler measurements of transiting planet-host stars. The sizes of the transiting planets range from Earth-size to larger than Jupiter (13 R is typical), while the orbital periods range from less than a day to a few months. For 32 of the planets, the Doppler signal was detected with significance greater than 5 (51 were detected with >3 significance). An important characteristic of this catalog is the use of uniform analysis procedures to determine stellar and planetary properties. This includes the transit search and fitting procedures applied to the K2 photometry, the Doppler fitting techniques applied to the radial velocities (RVs), and the spectral modeling to determine bulk stellar parameters. Such a uniform treatment will make the catalog useful for statistical studies of the masses, densities, and system architectures of exoplanetary systems. This work also serves as a data release for all previously unpublished RVs and associated stellar activity indicators obtained by our team for these systems, along with derived stellar and planet parameters.
  11. Thirouin, A., Noll, K., Grundy, W., Sheppard, S., Escarzaga, F., Donnelly, B., 2025, AJ, 169, 316, Logos-Zoe: A Contact Binary Triple System in the Trans-Neptunian Belt
    The trans-Neptunian object (58534) 1997 CQ29 (a.k.a. Logos) is a resolved wide binary in the dynamically Cold Classical population. With Hubble Space Telescope resolved observations where the primary Logos is well separated from its secondary Zoe it can be established that Logos has a time-variable brightness. Logos' brightness varied by several tenths of a magnitude over a short timescale of hours while the brightness variability of Zoe was on a longer timescale. New unresolved ground-based observations obtained with the Lowell Discovery Telescope and the Magellan-Baade telescope confirm at least one highly variable component in this system. With our ground-based observations and photometric constraints from space-based observations, we suggest that the primary Logos is likely a close/contact binary whose rotational period is 17.43 0.06 hr for a lightcurve amplitude of 0.70 0.07 mag, while Zoe is potentially a (very) slow rotator with an unknown shape. Using the Candela software, we model the Logos-Zoe system and predict its upcoming mutual events season using rotational, physical, and mutual orbit parameters derived in this work or already published. Zoe's shape and rotational period are still uncertain, so we consider various options to better understand Zoe. The upcoming mutual event season for Logos-Zoe starts in 2026 and will last for four years with up to two events per year. Observations of these mutual events will allow us to significantly improve the physical and rotational properties of both Logos and Zoe.
  12. Richey-Yowell, T., Shkolnik, E., Llama, J., Sikora, J., Smith, P., 2025, AJ, 169, 327, Stringent Limits on H 3+ Emission from the Hot Jupiters WASP-80b and WASP-69b
    Observations of auroras on exoplanets would provide numerous insights into planetstar systems, including potential detections of the planetary magnetic fields, constraints on host-star wind properties, and information on the thermal structures of planets. However, there have not yet been any discoveries of auroras on exoplanets. In this paper, we focus on the search for infrared auroral emission from the molecular ion H 3+ , which is common in the atmospheres of solar system planets Jupiter, Saturn, and Uranus. Using Keck/NIRSPEC high-resolution spectroscopy, we search for H 3+ emission from two hot Jupiters, WASP-80b and WASP-69b. We do not see any evidence of emission in the observed spectra when cross correlating with an H 3+ spectral model or when using an autocorrelation approach to search for any significant features. We therefore place upper limits on the total emission of 5.32 1018 W for WASP-80b and 1.64 1019 W for WASP-69b.These upper limits represent the most stringent limits to date and approach the regime of emission suspected from theoretical models.
  13. Ferreira, F., Camargo, J., Boufleur, R., Banda-Huarca, M., Pieres, A., Peixoto, V., Assafin, M., Bernardinelli, P., Lin, H., Braga-Ribas, F., Gomes-Junior, A., Vieira-Martins, R., da Costa, L., Abbott, T., Aguena, M., Allam, S., Alves, O., Annis, J., Bacon, D., Brooks, D., Burke, D., Carnero Rosell, A., Carretero, J., Desai, S., Doel, P., Everett, S., Ferrero, I., Frieman, J., Garcia-Bellido, J., Gatti, M., Gaztanaga, E., Giannini, G., Gruen, D., Gruendl, R., Herner, K., Hinton, S., Hollowood, D., Honscheid, K., James, D., Kuehn, K., Lee, S., Marshall, J., Mena-Fernandez, J., Miquel, R., Myles, J., Palmese, A., Plazas Malagon, A., Pereira, M., Samuroff, S., Sanchez, E., Sanchez Cid, D., Servila-Noarbe, I., Smith, M., Suchyta, E., Swanson, M., Tarle, G., To, C., Tucker, D., de Vicente, J., Vikram, V., Walker, A., Weaverdyck, N., 2025, MNRAS, 540, 460, Year six photometric measurements of known Trans-Neptunian Objects and Centaurs by the Dark Energy Survey
    We identified known Trans-Neptunian Objects (TNOs) and Centaurs in the complete Dark Energy Survey (DES) year six catalogue (DES Y6) through the Sky Body Tracker (SkyBoT) tool. We classified our data set of 144 objects into a widely used 4-class taxonomic system of TNOs. No such previous classification was available in the literature for most of these objects. From absolute magnitudes and average albedos, an estimation of the diameters of all these objects is obtained. Correlations involving colours, orbital parameters, dynamical classes, and sizes are also discussed. In particular, our largest reddest object has a diameter of $390^{+68}_{-53}$ km and our largest cold classical, $255^{+19}_{-17}$ km. Also, a weak correlation between colour and inclination is found within the population of resonant TNOs in addition to weak correlations between colour and phase slope in different bands.
  14. Rector, T., Prato, L., Kerr, R., Papraniku, E., Fisk, K., 2025, AJ, 169, 313, The HerbigHaro Outflow Content and Star-forming Environment of Circinus West and East
    We report the results of a spatially compete, high-sensitivity survey for HerbigHaro (HH) outflows in the Western and Eastern Circinus molecular clouds. We have detected 28 new HH objects in Circinus West, doubling the number known in this dark nebula. We have also discovered nine outflows in Circinus East, the first to be identified here. Although both Circinus West and East appear to be located at 800 pc, their morphologies are distinct. Circinus West shows filamentary structure, while Circinus East is dominated by amorphous dark clouds. NorthEast of Circinus East, an extended distribution of young stars is centered on the 6 Myr old open cluster ASCC 79, which may have triggered the sequential formation of younger surrounding populations. New transverse velocities from Gaia show two dynamically distinct stellar populations in Circinus East; their velocity distribution is consistent with an active cloud-cloud collision between material ejected by the formation of O and B stars in ASCC 79, and a dynamically similar interloping cloud. Given the similar distances to Circinus West and East, and the presence in both of HH objectsa phenomenon associated with stellar ages of 1 Myrit is likely that these clouds are nominally related, but only Circinus East is subject to substantial feedback from the central cluster in the parent complex. This feedback appears to guide the morphology and evolution of Circinus East, resulting in a complex and possibly disruptive dynamical environment rich in star-formation potential that contrasts with the relatively quiescent environment in Circinus West.
  15. Archer, H., Hunter, D., Elmegreen, B., Hunt, L., O'Brien, R., Brinks, E., Cigan, P., Rubio, M., Windhorst, R., Jansen, R., Mathews, E., 2025, AJ, 169, 301, Stellar Populations and Molecular Gas Composition in the Low-metallicity Environment of WLM
    We investigate the stellar populations and molecular gas properties of a star-forming region within the dwarf irregular (dIrr) galaxy WolfLundmarkMellote (WLM). Low-metallicity dIrrs like WLM offer a valuable window into star formation in environments that are unlike those of larger, metal-rich galaxies such as the Milky Way. In these conditions, carbon monoxide (CO), typically used to trace molecular clouds, is more easily photodissociated by ultraviolet (UV) radiation, leading to a larger fraction of CO-dark molecular gas, where H2 exists without detectable CO emission, or CO-dark gas in the form of cold H I. Understanding the molecular gas content and the stellar populations in these star-forming regions provides important information about the role of CO-bright and CO-dark gas in forming stars. Using Hubble Space Telescope imaging across five Wide Field Camera 3 UVIS bands and CO observations from the Atacama Large Millimeter Array, we examine stellar populations within and outside CO cores and the photodissociation region. Our findings indicate similar physical characteristics such as age and mass across the different environments. Assuming 2% of molecular gas is converted to stars, we estimate the molecular gas content and determine that CO-dark gas constitutes a large fraction of the molecular reservoir in WLM. These results are consistent with molecular gas estimates using a previous dust-derived CO-to-H2 conversion factor (CO) for WLM. These findings highlight the critical role of CO-dark gas in low-metallicity star formation.
  16. Bernardinelli, P., Bernstein, G., Abbott, T., Aguena, M., Allam, S., Brooks, D., Carnero Rosell, A., Carretero, J., da Costa, L., Pereira, M., Davis, T., De Vicente, J., Desai, S., Diehl, H., Doel, P., Everett, S., Flaugher, B., Frieman, J., Garcia-Bellido, J., Gaztanaga, E., Gruendl, R., Gutierrez, G., Herner, K., Hinton, S., Hollowood, D., Honscheid, K., James, D., Kuehn, K., Lahav, O., Lee, S., Marshall, J., Mena-Fernandez, J., Miquel, R., Myles, J., Plazas Malagon, A., Samuroff, S., Sanchez, E., Santiago, B., Sevilla-Noarbe, I., Smith, M., Suchyta, E., Tarle, G., Tucker, D., Vikram, V., Walker, A., Weaverdyck, N., DES Collaboration, 2025, AJ, 169, 305, Photometry of Outer Solar System Objects from the Dark Energy Survey. II. A Joint Analysis of Trans-Neptunian Absolute Magnitudes, Colors, Light Curves and Dynamics
    For the 696 trans-Neptunian objects (TNOs) with absolute magnitudes 5.5 < Hr < 8.2 detected in the Dark Energy Survey, we characterize the relationships between their dynamical state and physical propertiesnamely Hr, indicating size; colors, indicating surface composition; and flux variation semiamplitude A, indicating asphericity and surface inhomogeneity. We seek "birth" physical distributions that can recreate these parameters in every dynamical class. We show that the observed colors of these TNOs are consistent with two Gaussian distributions in griz space, "near-infrared bright" (NIRB) and "near-infrared faint" (NIRF), presumably an inner and outer birth population, respectively. We find a model in which both the NIRB and NIRF Hr and A distributions are independent of current dynamical states, supporting their assignment as birth populations. All objects are consistent with a common rolling p(Hr), but NIRF objects are significantly more variable. Cold classicals (CCs) are purely NIRF, while hot classical (HC), scattered, and detached TNOs are consistent with 70% NIRB and the resonance NIRB fractions show significant variation. The NIRB components of the HCs and of some resonances have broader inclination distributions than the NIRFs, i.e. their current dynamics retains information about birth location. We find evidence for radial stratification within the birth NIRB population, in that HC NIRBs are on average redder than detached or scattered NIRBs; a similar effect distinguishes CCs from other NIRFs. We estimate total object counts and masses of each class within our Hr range. These results will strongly constrain models of the outer solar system.
  17. Slyusarev, I., Shevchenko, V., Belskaya, I., Krugly, Y., Chiorny, V., Mikhalchenko, O., Inasaridze, R., Ayvaczian, V., Zhuzhunadze, V., Reva, I., Omarov, C., Kwiatkowski, T., Oszkiewicz, D., Troianskyi, V., Skiff, B., Maryeva, O., Karpov, S., Donchev, Z., 2025, P&SS, 260, 106103, Opposition effect of M-type asteroids
    We present results of the observational program dedicated to search for possible diversity in opposition effect behavior of M-type asteroids. New photometric BVR observations were obtained for 10 asteroids, (325) Heidelberga, (382) Dodona, (558) Carmen, (639) Latona, (758) Mancunia, (789) Lena, (1046) Edwin, (1352) Wawel, (2582) Harimaya-Bashi, and (5615) Iskander. Five of these asteroids have diameters in the range from 5 to 40 km. For all of observed asteroids, we obtained lightcurves and magnitude-phase curves in a wide range of phase angles. We determined values of rotation periods and absolute magnitudes of these asteroids. With our new data, we doubled the number of M-type asteroids with measured opposition effect and for the first time observed opposition effect of M-type asteroids less than 40 km in diameter. We found that three asteroids, (558) Carmen, (789) Lena and (5615) Iskander, exhibit lower values of opposition effect compared to other measured M- and S-type asteroids but the slope of the linear part of the phase curve is typical for moderate-albedo surfaces. A possible explanation of their lower opposition effect is an assumption of a higher metal content on their surfaces as compared to other asteroids.

    18. 17 publications and 7 citations in 2025.

17 publications and 7 citations total.

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