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2025

1. Henault, E., Brunetto, R., Pinilla-Alonso, N., Baklouti, D., Djouadi, Z., Guilbert-Lepoutre, A., Muller, T., Cryan, S., de Souza-Feliciano, A., Holler, B., de Pra, M., Emery, J., McClure, L., Schambeau, C., Pendleton, Y., Harvison, B., Licandro, J., Lorenzi, V., Cruikshank, D., Peixinho, N., Bannister, M., Stansberry, J., 2025, A&A, 694, A126, Irradiation origin and stability of CO on trans-Neptunian objects: Laboratory constraints and observational evidence from JWST/DiSCo-TNOs
   Abstract

   Context. The James Webb Space Telescope large program DiSCo-TNOs has recently shown that CO₂ ice is ubiquitous on 54 mediumsize trans-Neptunian objects (TNOs). TNO surfaces are found to define three main spectral and thus compositional groups that are likely linked to their position before planetary migration. CO ice is observed on the spectral type that is richest in CO₂ and on the type that is richer in CH₃OH and organics. Considerations on the thermal evolution of TNOs predicted the depletion of hypervolatiles such as CO from their surface layers, however. Aims. We investigate a potential irradiation origin of CO as well as its stability by studying the distribution of CO in two TNO compositional types and compared it with irradiation experiments. Methods. We studied the 4.68 m band of CO and the 2.70 m band of CO₂ to probe the relation between the two molecules in 33 TNOs. We performed ion irradiation experiments on CO₂ and CH₃OH ices at 45 and 60 K with 30 keV H⁺ . We compared the laboratory spectra to TNO observations by focusing on the band areas and positions. Results. We find that the two types of surfaces in which CO is detected are very distinct in terms of their relative abundances and chemical environment. CO that is observed on surfaces that are rich in CO₂ are consistent with being produced by CO₂ irradiation, specifically, at 45 K. On objects that are rich in CH₃OH and complex organics, CO is more likely formed by irradiation of CH₃OH. As the CO band areas are only partly related with temperature, the chemical environment plays a major role in the CO retention. Conclusions. We find that the CO that is observed on TNO surfaces is compatible with being a secondary molecule that is entirely formed by late irradiation processes. Its abundance and stability is mostly controlled by the matrix from which it formed.

2. Thomas, L., Hebrard, G., Kellermann, H., Korth, J., Heidari, N., Forveille, T., Sousa, S., Scholler, L., Riffeser, A., Gossl, C., Serrano Bell, J., Kiefer, F., Hara, N., Grupp, F., Ehrhardt, J., Murgas, F., Collins, K., Bieryla, A., Parviainen, H., Belinski, A., Esparza-Borges, E., Ciardi, D., Clark, C., Fukui, A., Gilbert, E., Hopp, U., Ikuta, K., Jenkins, J., Latham, D., Narita, N., Nielsen, L., Quinn, S., Palle, E., Pippert, J., Polanski, A., Ries, C., Schmidt, M., Schwarz, R., Seager, S., Strakhov, I., Striegel, S., van Eyken, J., Watanabe, N., Watkins, C., Winn, J., Ziegler, C., Zoller, R., 2025, A&A, 694, A143, TOI-5108 b and TOI 5786 b: Two transiting sub-Saturns detected and characterized with TESS, MaHPS, and SOPHIE
   Abstract

   We report the discovery and characterization of two sub-Saturns from the Transiting Exoplanet Survey Satellite (TESS) using high- resolution spectroscopic observations from the MaHPS spectrograph at the Wendelstein Observatory and the SOPHIE spectrograph at the Haute-Provence Observatory. Combining photometry from TESS, KeplerCam, LCOGT, and MuSCAT2, along with the radial velocity measurements from MaHPS and SOPHIE, we measured precise radii and masses for both planets. TOI-5108 b is a sub-Saturn, with a radius of 6.6 0.1 R and a mass of 32 5 M. TOI-5786 b is similar to Saturn, with a radius of 8.54 0.13 R and a mass of 73 9 M. The host star for TOI-5108 b is a moderately bright (Vmag 9.75) G-type star. TOI-5786 is a slightly dimmer (Vmag 10.2) F-type star. Both planets are close to their host stars, with periods of 6.75 days and 12.78 days, respectively. This puts TOI-5108 b just within the bounds of the Neptune desert, while TOI-5786 b is right above the upper edge. We estimated hydrogen-helium (H/He) envelope mass fractions of 38% for TOI-5108 b and 74% for TOI-5786 b. However, when using a model for the interior structure that includes tidal effects, the envelope fraction of TOI-5108 b could be much lower (~20%), depending on the obliquity. We estimated mass-loss rates between 1.0 x 10⁹ g/s and 9.8 x 10⁹ g/s for TOI-5108 b and between 3.6 x 10⁸ g/s and 3.5 x 10⁹ g/s for TOI-5786 b. Given their masses, both planets could be stable against photoevaporation. Furthermore, at these mass-loss rates, there is likely no detectable signal in the metastable helium triplet with the James Webb Space Telescope (JWST). We also detected a transit signal for a second planet candidate in the TESS data of TOI-5786, with a period of 6.998 days and a radius of 3.83 0.16 R. Using our RV data and photodynamical modeling, we were able to provide a 3- upper limit of 26.5 M for the mass of the potential inner companion to TOI-5786 b.

3. Golden-Marx, J., Zhang, Y., Ogando, R., Yanny, B., Pereira, M., Hilton, M., Aguena, M., Allam, S., Andrade-Oliveira, F., Bacon, D., Brooks, D., Carnero Rosell, A., Carretero, J., Cheng, T., da Costa, L., De Vicente, J., Desai, S., Doel, P., Everett, S., Ferrero, I., Frieman, J., Garcia-Bellido, J., Gatti, M., Giannini, G., Gruen, D., Gruendl, R., Gutierrez, G., Hinton, S., Hollowood, D., Honscheid, K., James, D., Kuehn, K., Lee, S., Mena-Fernandez, J., Menanteau, F., Miquel, R., Mohr, J., Palmese, A., Pieres, A., Plazas Malagon, A., Samuroff, S., Sanchez, E., Schubnell, M., Sevilla-Noarbe, I., Smith, M., Suchyta, E., Tarle, G., Vikram, V., Walker, A., Weaverdyck, N., Wiseman, P., 2025, MNRAS, The Hierarchical Growth of Bright Central Galaxies and Intracluster Light as Traced by the Magnitude Gap
   Abstract

   Using a sample of 2800 galaxy clusters identified in the Dark Energy Survey across the redshift range 0.20 < z < 0.60, we characterize the hierarchical assembly of Bright Central Galaxies (BCGs) and the surrounding intracluster light (ICL). To quantify hierarchical formation we use the stellar mass - halo mass (SMHM) relation, comparing the halo mass, estimated via the mass-richness relation, to the stellar mass within the BCG+ICL system. Moreover, we incorporate the magnitude gap (M14), the difference in brightness between the BCG (measured within 30 kpc) and 4th brightest cluster member galaxy within 0.5 R_{200, c}, as a third parameter in this linear relation. The inclusion of M14, which traces BCG hierarchical growth, increases the slope and decreases the intrinsic scatter, highlighting that it is a latent variable within the BCG+ICL SMHM relation. Moreover, the correlation with M14 decreases at large radii. However, the stellar light within the BCG+ICL transition region (30 kpc - 80 kpc) most strongly correlates with halo mass and has a statistically significant correlation with M14. Since the transition region and M14 are independent measurements, the transition region may grow due to the BCG's hierarchical formation. Additionally, as M14 and ICL result from hierarchical growth, we use a stacked sample and find that clusters with large M14 values are characterized by larger ICL and BCG+ICL fractions, which illustrates that the merger processes that build the BCG stellar mass also grow the ICL. Furthermore, this may suggest that M14 combined with the ICL fraction can identify dynamically relaxed clusters.

4. Dixon, M., Mould, J., Lidman, C., Taylor, E., Flynn, C., Duffy, A., Galbany, L., Scolnic, D., Davis, T., Moller, A., Kelsey, L., Lee, J., Wiseman, P., Vincenzi, M., Shah, P., Aguena, M., Allam, S., Alves, O., Bacon, D., Bocquet, S., Brooks, D., Burke, D., Carnero Rosell, A., Carollo, D., Carretero, J., Conselice, C., da Costa, L., Pereira, M., Diehl, H., Doel, P., Everett, S., Ferrero, I., Flaugher, B., Frieman, J., Garcia-Bellido, J., Gatti, M., Gaztanaga, E., Giannini, G., Gruen, D., Gruendl, R., Gutierrez, G., Herner, K., Hinton, S., Hollowood, D., Honscheid, K., James, D., Kuehn, K., Lima, M., Marshall, J., Mena-Fernandez, J., Menanteau, F., Miquel, R., Myles, J., Nichol, R., Ogando, R., Palmese, A., Pieres, A., Plazas Malagon, A., Samuroff, S., Sanchez, E., Sanchez Cid, D., Sevilla-Noarbe, I., Smith, M., Sobreira, F., Suchyta, E., Swanson, M., Tarle, G., To, C., Tucker, B., Tucker, D., Vikram, V., Walker, A., Weaverdyck, N., 2025, MNRAS, Calibrating the absolute magnitude of type Ia supernovae in nearby galaxies using [OII] and implications for H₀
   Abstract

   The present state of cosmology is facing a crisis where there is a fundamental disagreement in measurements of the Hubble constant (H₀), with significant tension between the early and late universe methods. Type Ia supernovae (SNe Ia) are important to measuring H₀ through the astronomical distance ladder. However, there remains potential to better standardise SN Ia light curves by using known dependencies on host galaxy properties after the standard light curve width and colour corrections have been applied to the peak SN Ia luminosities. To explore this, we use the 5-year photometrically identified SNe Ia sample obtained by the Dark Energy Survey, along with host galaxy spectra obtained by the Australian Dark Energy Survey. Using host galaxy spectroscopy, we find a significant trend with the equivalent width (EW) of the [OII] 3727, 29 doublet, a proxy for specific star formation rate, and Hubble residuals. We find that the correlation with [OII] EW is a powerful alternative to the commonly used mass step after initial light curve corrections. Applying this [OII] EW correction to 20 SNe Ia in calibrator galaxies observed with WiFeS, we examined the impact on SN Ia absolute magnitudes and H₀. Our [OII] EW corrections result in H₀ values ranging between 73.04 to 73.51kms^-1Mpc^-1, with a combined statistical and systematic uncertainty of ~1.31kms^-1Mpc^-1. However, even with this additional correction, the impact of host galaxy properties in standardising SNe Ia appears limited in reducing the current tension (~5) with the CMB result for H₀.

5. Burdanov, A., de Wit, J., Broz, M., Muller, T., Hoffmann, T., Ferrais, M., Micheli, M., Jehin, E., Parrott, D., Hasler, S., Binzel, R., Ducrot, E., Kreidberg, L., Gillon, M., Greene, T., Grundy, W., Kareta, T., Lagage, P., Moskovitz, N., Thirouin, A., Thomas, C., Zieba, S., 2025, Natur, 638, 74, JWST sighting of decametre main-belt asteroids and view on meteorite sources
   Abstract

   Asteroid discoveries are essential for planetary-defence efforts aiming to prevent impacts with Earth¹, including the more frequent² megaton explosions from decametre impactors^{3, 4, 56}. Although large asteroids (100 kilometres) have remained in the main belt since their formation⁷, small asteroids are commonly transported to the near-Earth object (NEO) population^8,9. However, owing to the lack of direct observational constraints, their sizefrequency distribution (SFD)which informs our understanding of the NEOs and the delivery of meteorite samples to Earthvaries substantially among models^{10, 11, 12, 1314}. Here we report 138 detections of some of the smallest asteroids (10 metres) ever observed in the main belt, which were enabled by JWST's infrared capabilities covering the emission peaks of the asteroids¹⁵ and synthetic tracking techniques^{16, 1718}. Despite small orbital arcs, we constrain the distances and phase angles of the objects using known asteroids as proxies, allowing us to derive sizes through radiometric techniques. Their SFD shows a break at about 100 metres (debiased cumulative slopes of q = 2.66 0.60 and 0.97 0.14 for diameters smaller and larger than roughly 100 metres, respectively), suggestive of a population driven by collisional cascade. These asteroids were sampled from several asteroid familiesmost probably Nysa, Polana and Massaliaaccording to the geometry of pointings considered here. Through further long-stare infrared observations, JWST is poised to serendipitously detect thousands of decametre-scale asteroids across the sky, examining individual asteroid families¹⁹ and the source regions of meteorites^13,14 'in situ'.

6. Camilleri, R., Davis, T., Hinton, S., Armstrong, P., Brout, D., Galbany, L., Glazebrook, K., Lee, J., Lidman, C., Moller, A., Nichol, R., Sako, M., Scolnic, D., Shah, P., Smith, M., Sullivan, M., Sanchez, B., Vincenzi, M., Wiseman, P., Allam, S., Abbott, T., Aguena, M., Andrade-Oliveira, F., Asorey, J., Avila, S., Bacon, D., Bechtol, K., Bocquet, S., Brooks, D., Buckley-Geer, E., Burke, D., Rosell, A., Carollo, D., Carretero, J., Castander, F., Conselice, C., da Costa, L., Pereira, M., Desai, S., Diehl, H., Everett, S., Ferrero, I., Flaugher, B., Frieman, J., Garcia-Bellido, J., Gaztanaga, E., Giannini, G., Gruendl, R., Herner, K., Hollowood, D., Honscheid, K., Huterer, D., James, D., Kent, S., Kuehn, K., Lahav, O., Lee, S., Lewis, G., Lima, M., Marshall, J., Mena-Fernandez, J., Miquel, R., Myles, J., Ogando, R., Palmese, A., Pieres, A., Plazas Malagon, A., Romer, A., Roodman, A., Samuroff, S., Sanchez, E., Sanchez Cid, D., Schubnell, M., Sevilla-Noarbe, I., Suchyta, E., Suntzeff, N., Swanson, M., Tarle, G., Tucker, B., Walker, A., Weaverdyck, N., DES Collaboration, 2025, MNRAS, 537, 1818, The Dark Energy Survey Supernova Program: an updated measurement of the Hubble constant using the inverse distance ladder
   Abstract

   We measure the current expansion rate of the Universe, Hubble's constant $H_0$, by calibrating the absolute magnitudes of supernovae to distances measured by baryon acoustic oscillations (BAO). This 'inverse distance ladder' technique provides an alternative to calibrating supernovae using nearby absolute distance measurements, replacing the calibration with a high-redshift anchor. We use the recent release of 1829 supernovae from the Dark Energy Survey spanning $0.01\lt z\lt 1.13$ anchored to the recent baryon acoustic oscillation measurements from Dark Energy Spectroscopic Instrument (DESI) spanning $0.30 \lt z_{\mathrm{eff}}\lt 2.33$. To trace cosmology to $z=0$, we use the third-, fourth-, and fifth-order cosmographic models, which, by design, are agnostic about the energy content and expansion history of the universe. With the inclusion of the higher redshift DESI-BAO data, the third-order model is a poor fit to both data sets, with the fourth-order model being preferred by the Akaike Information Criterion. Using the fourth-order cosmographic model, we find $H_0=67.19^{+0.66}_{-0.64}\mathrm{~km} \mathrm{~s}^{-1} \mathrm{~Mpc}^{-1}$, in agreement with the value found by Planck without the need to assume Flat-$\Lambda$CDM. However, the best-fitting expansion history differs from that of Planck, providing continued motivation to investigate these tensions.

7. Battle, A., Reddy, V., Sanchez, J., Pearson, N., Sharkey, B., Kareta, T., 2025, PSJ, 6, 31, Long-term Spectral Monitoring of Active Asteroid (6478) Gault: Implications for the H Chondrite Parent Body
   Abstract

   Active asteroid (6478) Gault underwent outbursts between late 2018 and early 2019 with tails morphologically similar to the ejecta from Dimorphous following the Double Asteroid Redirection Test impact. Multiple studies investigated the dust properties, confirmed that Gault is an S-type Phocaea-family asteroid, and obtained a 2.5 hr rotation period consistent with being near the critical rotation period for breakup. We present results from near-infrared spectral monitoring of Gault on one night during a period of activity and five nights across 3 yr after activity ceased in order to understand the evolution of surface mineralogy over time. Spectral band parameters show an average Band I center of 0.920 0.005 m, Band II center of 2.04 0.13 m, and band area ratio of 1.33 0.04. These values correspond to an olivinepyroxene ratio of 0.40, 18.7 mol% fayalite, and 17.2 mol% ferrosiliteall of which are consistent with an H chondrite that has low levels of thermal metamorphism. Three meteorite analogs were identified that are H chondrites with petrologic types between H3.4 and H4. The low-level thermal metamorphism interpretation of Gault's surface suggests that it formed from the outermost portion of the progenitor of the Phocaea family, assuming an "onion shell' structure, which was catastrophically disrupted 1.2 Gyr ago. We discuss implications of Gault's surface composition to better understand this H chondrite parent body, with the suggestion that more dynamical and spectral analyses be performed for members of the Phocaea family.

8. Corbett, T., Doner, A., Horanyi, M., Brandt, P., Grundy, W., Lisse, C., Parker, J., Peltier, L., Poppe, A., Singer, K., Stern, S., Verbiscer, A., 2025, ApJL, 979, L50, Production, Transport, and Destruction of Dust in the Kuiper Belt: The Effects of Refractory and Volatile Grain Compositions
   Abstract

   The Venetia Burney Student Dust Counter (SDC) on board the New Horizons spacecraft measures the spatial and size distributions of dust along its trajectory. Models based on early SDC measurements predicted a peak dust number density at a heliocentric distance of 40 au, followed by a rapid decline. Instead, SDC observed dust fluxes 23 times higher than predicted between 40 and 60 au. One potential explanation for this discrepancy is that SDC may be encountering icy grains with different dynamical behavior than previously modeled silicate grains. Due to ultraviolet photosputtering, waterice grains rapidly erode and migrate outward, significantly contributing to the measured dust number densities only at distances 40 au. We present a model of silicate and ice grain dynamics in the outer solar system, considering gravitational and radiation forces and grain erosion. Using SDC data, we estimate that the mass production rate of ice grains between 0.1 and 10 m in the Kuiper Belt (KB) would need to be 2070 times higher than that of silicate grains. However, KB grains are expected to be refractory/volatile mixtures rather than pure silicate or ice. Thus, we briefly explore simple models of more realistic mixed-grain cases to further gauge the effects of grain composition on the equilibrium dust distribution. Future SDC measurements at greater distances will test the model predictions and further constrain silicate and ice grain production rates in the KB.

9. Crossfield, I., Polanski, A., Robertson, P., Murphy, J., Turtelboom, E., Luque, R., Beatty, T., Daylan, T., Isaacson, H., Brande, J., Kreidberg, L., Batalha, N., Huber, D., Rhem, M., Dressing, C., Kane, S., Bossett, M., Gagnebin, A., Kroft, M., Premnath, P., Rogers, C., Collins, K., Latham, D., Watkins, C., Ciardi, D., Howell, S., Savel, A., Berlind, P., Calkins, M., Esquerdo, G., Mink, J., Clark, C., Lund, M., Matson, R., Everett, M., Schlieder, J., Matthews, E., Giacalone, S., Barclay, T., Zambelli, R., Plavchan, P., Ellingson, T., Bowen, M., Srdoc, G., McLeod, K., Schwarz, R., Barkaoui, K., Kamler, J., Murgas, F., Palle, E., Narita, N., Fukui, A., Relles, H., Bieryla, A., Girardin, E., Massey, B., Stockdale, C., Lewin, P., Papini, R., Guerra, P., Conti, D., Yalcinkaya, S., Basturk, O., Mourad, G., 2025, AJ, 169, 89, OrCAS: Origins, Compositions, and Atmospheres of Sub-Neptunes. I. Survey Definition
   Abstract

   Sub-Neptunesvolatile-rich exoplanets smaller than Neptuneare intrinsically the most common type of planet known. However, the formation and nature of these objects, as well as the distinctions between subclasses (if any), remain unclear. Two powerful tools to tease out the secrets of these worlds are measurements of (i) atmospheric composition and structure revealed by transit and/or eclipse spectroscopy, and (ii) mass, radius, and density revealed by transit photometry and Doppler spectroscopy. Here, we present OrCAS, a survey to better elucidate the origins, compositions, and atmospheres of sub-Neptunes. This radial velocity survey uses a repeatable, quantifiable metric to select targets suitable for subsequent transmission spectroscopy and address key science themes about the atmospheric and internal compositions and architectures of these systems. Our survey targets 26 systems with transiting sub-Neptune planet candidates, with the overarching goal of increasing the sample of such planets suitable for subsequent atmospheric characterization. This paper lays out our survey's science goals, defines our target prioritization metric, and performs light-curve fits and statistical validation using existing TESS photometry and ground-based follow-up observations. Our survey serves to continue expanding the sample of small exoplanets with well-measured properties orbiting nearby bright stars, ensuring fruitful studies of these systems for many years to come.

10. Kareta, T., Fuentes-Munoz, O., Moskovitz, N., Farnocchia, D., Sharkey, B., 2025, ApJL, 979, L8, On the Lunar Origin of Near-Earth Asteroid 2024 PT5
    Abstract

    The near-Earth asteroid (NEA) 2024 PT5 is on an Earth-like orbit that remained in Earth's immediate vicinity for several months at the end of 2024. PT5's orbit is challenging to populate with asteroids originating from the main belt and is more commonly associated with rocket bodies mistakenly identified as natural objects or with debris ejected from impacts on the Moon. We obtained visible and near-infrared reflectance spectra of PT5 with the Lowell Discovery Telescope and NASA Infrared Telescope Facility on 2024 August 16. The combined reflectance spectrum matches lunar samples but does not match any known asteroid typesit is pyroxene-rich, while asteroids of comparable spectral redness are olivine-rich. Moreover, the amount of solar radiation pressure observed on the PT5 trajectory is orders of magnitude lower than what would be expected for an artificial object. We therefore conclude that 2024 PT5 is ejecta from an impact on the Moon, thus making PT5 the second NEA suggested to be sourced from the surface of the Moon. While one object might be an outlier, two suggest that there is an underlying population to be characterized. Long-term predictions of the position of 2024 PT5 are challenging due to the slow Earth encounters characteristic of objects in these orbits. A population of near-Earth objects that are sourced by the Moon would be important to characterize for understanding how impacts work on our nearest neighbor and for identifying the source regions of asteroids and meteorites from this understudied population of objects on very Earth-like orbits.

11. Tang, S., Johns-Krull, C., Prato, L., Stahl, A., 2025, ApJ, 978, 119, Erratum: "Measuring the Spot Variability of T Tauri Stars Using Near-infrared Atomic Fe and Molecular OH Lines" (2024, ApJ, 973, 124)
    Abstract

    No abstract found.

12. Esteves, J., Pereira, M., Soares-Santos, M., Annis, J., Welch, B., Wu, H., Palmese, A., Farahi, A., Andrade-Oliveira, F., Lin, H., Garcia-Bellido, J., Aguena, M., Alves, O., Bacon, D., Bocquet, S., Brooks, D., Carnero Rosell, A., Carretero, J., Costanzi, M., da Costa, L., De Vicente, J., Doel, P., Everett, S., Flaugher, B., Frieman, J., Gruen, D., Gruendl, R., Gutierrez, G., Hinton, S., Hollowood, D., Honscheid, K., James, D., Kuehn, K., Lidman, C., Lima, M., Marshall, J., Mena-Fernandez, J., Miquel, R., Myles, J., Ogando, R., Pieres, A., Plazas Malagon, A., Romer, A., Sanchez, E., Sanchez Cid, D., Santiago, B., Schubnell, M., Sevilla-Noarbe, I., Smith, M., Suchyta, E., Swanson, M., Weaverdyck, N., Wiseman, P., Yamamoto, M., DES Collaboration, 2025, MNRAS, 536, 931, Copacabana: a probabilistic membership assignment method for galaxy clusters
    Abstract

    Cosmological analyses using galaxy clusters in optical/near-infrared photometric surveys require robust characterization of their galaxy content. Precisely determining which galaxies belong to a cluster is crucial. In this paper, we present the COlor Probabilistic Assignment of Clusters And BAyesiaN Analysis (Copacabana) algorithm. Copacabana computes membership probabilities for all galaxies within an aperture centred on the cluster using photometric redshifts, colours, and projected radial probability density functions. We use simulations to validate Copacabana and we show that it achieves up to 89 per cent membership accuracy with a mild dependence on photometric redshift uncertainties and choice of aperture size. We find that the precision of the photometric redshifts has the largest impact on the determination of the membership probabilities followed by the choice of the cluster aperture size. We also quantify how much these uncertainties in the membership probabilities affect the stellar mass-cluster mass scaling relation, a relation that directly impacts cosmology. Using the sum of the stellar masses weighted by membership probabilities ($\rm \mu _{\star }$) as the observable, we find that Copacabana can reach an accuracy of 0.06 dex in the measurement of the scaling relation at low redshift for a Legacy Survey of Space and Time type survey. These results indicate the potential of Copacabana and $\rm \mu _{\star }$ to be used in cosmological analyses of optically selected clusters in the future.

13. Simon, A., Kaplan, H., Reuter, D., Montanaro, M., Grundy, W., Lunsford, A., Weigle, G., Binzel, R., Emery, J., Sunshine, J., Howett, C., Levison, H., Marchi, S., Noll, K., Spencer, J., 2025, PSJ, 6, 7, Lucy L'Ralph In-flight Calibration and Results at (152830) Dinkinesh
    Abstract

    The L'Ralph instrument is a key component of NASA's Lucy mission, intended to provide spectral image data of multiple Jupiter Trojans. The instrument operates from 0.35 to 4 m using two focal plane assemblies: a 350950 nm multispectral imager, Multi-spectral Visible Imaging Camera (MVIC), and a 0.974 m imaging spectrometer, Linear Etalon Imaging Spectral Array (LEISA). Instrument calibration was established through ground testing before launch and has been monitored during cruise utilizing internal calibration sources and stellar targets. In-flight data have shown that the instrument thermal performance is exceeding expectations, allowing for early updates to LEISA radiometric and pointing calibrations. MVIC radiometric performance remains stable more than 3 yr since launch. The serendipitous identification of a new flyby target, (152830) Dinkinesh, allowed testing of instrument performance and interleaved LEISA and MVIC acquisitions on an asteroid target. Both MVIC and LEISA obtained data of Dinkinesh and its moon, Selam, demonstrating that they show good spectral agreement with an S- or Sq-type asteroid, along with evidence of a 3 m absorption feature.

14. Chandler, C., Sedaghat, N., Oldroyd, W., Frissell, M., Trujillo, C., Burris, W., Hsieh, H., Kueny, J., Farrell, K., Borisov, G., DeSpain, J., Bernardinelli, P., Kurlander, J., Magbanua, M., Sheppard, S., Mazzucato, M., Bosch, M., Shaw-Diaz, T., Gonano, V., Lamperti, A., da Silva Campos, J., Goodwin, B., Terentev, I., Dukes, C., 2025, RNAAS, 9, 3, AI-enhanced Citizen Science Discovers Cometary Activity on Near-Earth Object (523822) 2012 DG61
    Abstract

    We report the discovery of cometary activity in the form of a pronounced tail emanating from Near-Earth Object (523822) 2012 DG₆₁, identified in UT 2024 April 18 Dark Energy Camera images by our AI assistant TailNet. TailNet is an AI designed to filter out images unlikely to show activity for volunteers of our NASA Partner "Active Asteroids" Citizen Science campaign, from which our AI is trained. Subsequently, our archival investigation revealed 2012 DG61 is recurrently active after we found it displaying a pronounced tail in a UT 2018 April 16 Steward Observatory Bart Bok 2.3 m telescope image and UT 2018 May 14 observations by G. Borisov with the 0.3 m telescope at MARGO Observatory. Our dynamical integrations reveal that 2012 DG61, an Apollo dynamical class member, is likely in 2:1 mean-motion resonance with Jupiter. We encourage additional observations to help characterize the activity morphology of this near-Earth comet.

15. Jenniskens, P., Johannink, C., Moskovitz, N., Howell, A., 2025, eMetN, 10, 20, Short note on what appears to have been a 2024 outburst of epsilon-Ursae-Minorids (IAU#1044)
    Abstract

    A meteor outburst with a radiant in Ursa Minor was detected by low-light level video cameras of the Global Meteor Network and by Belarusian and Ukranian meteor camera networks on September 2325, 2024. Here, we report on the results from the CAMS network and discuss the possible association with the epsilon-Ursae-Minorids outburst observed in 2019. If this is the same stream, a return of the shower is expected in 2025, and again in 2030/2031.

16. Awad, P., Li, T., Erkal, D., Peletier, R., Bunte, K., Koposov, S., Li, A., Balbinot, E., Smith, R., Canducci, M., Tino, P., Senkevich, A., Cullinane, L., Da Costa, G., Ji, A., Kuehn, K., Lewis, G., Pace, A., Zucker, D., Bland-Hawthorn, J., Limberg, G., Martell, S., McKenzie, M., Yang, Y., Usman, S., 2025, A&A, 693, A69, S⁵: New insights from deep spectroscopic observations of the tidal tails of the globular clusters NGC 1261 and NGC 1904
    Abstract

    As globular clusters (GCs) orbit the Milky Way, their stars are tidally stripped and form tidal tails that follow the orbit of the cluster around the Galaxy. The morphology of these tails is complex and shows correlations with the phase of orbit and the orbital angular velocity, especially for GCs on eccentric orbits. Here we focus on two GCs, NGC 1261 and NGC 1904, that were potentially accreted alongside Gaia-Enceladus and that have shown signatures of having, in addition to tidal tails, structures formed by distributions of extra-tidal stars that are misaligned with the general direction of the clusters' respective orbits. To provide an explanation for the formation of these structures, we made use of spectroscopic measurements from the Southern Stellar Stream Spectroscopic Survey (S⁵) as well as proper motion measurements from Gaia's third data release (DR3), and applied a Bayesian mixture modelling approach to isolate high-probability member stars. We recovered extra-tidal features surrounding each cluster matching findings from previous work. We then conducted N-body simulations and compared the expected spatial distribution and variation in the dynamical parameters along the orbit with those of our potential member sample. Furthermore, we used Dark Energy Camera (DECam) photometry to inspect the distribution of the member stars in the colour-magnitude diagram (CMD). We find that potential members agree reasonably with the N-body simulations, and that the majority follow a simple stellar population distribution in the CMD, which is characteristic of GCs. We link the extra-tidal features with their orbital properties and find that the presence of the tails agrees well with the theory of stellar stream formation through tidal disruption. In the case of NGC 1904, we clearly detect the tidal debris escaping the inner and outer Lagrange points, which are expected to be prominent when at or close to the apocentre of its orbit. Our analysis allows for further exploration of other GCs in the Milky Way that exhibit similar extra-tidal features.

17. Hsieh, H., Noonan, J., Kelley, M., Bodewits, D., Pittichova, J., Thirouin, A., Micheli, M., Knight, M., Bannister, M., Chandler, C., Holt, C., Hopkins, M., Kim, Y., Moskovitz, N., Oldroyd, W., Patterson, J., Sheppard, S., Tan, N., Trujillo, C., Ye, Q., 2025, PSJ, 6, 3, The Volatile Composition and Activity Evolution of Main-belt Comet 358P/PANSTARRS
    Abstract

    We report the detection of water vapor associated with main-belt comet 358P/PANSTARRS on UT 2024 January 89 using the NIRSPEC instrument on board JWST. We derive a water production rate of molecules s¹, marking only the second direct detection of sublimation products of any kind from a main-belt comet, after 238P/Read. Similar to 238P, we find a remarkable absence of hypervolatile species, finding molecules s¹, corresponding to %. Upper limits on CH₃OH and CO emission are also estimated. Photometry from ground-based observations shows that the dust coma brightened and faded slowly over 250 days in 20232024, consistent with photometric behavior observed in 20122013, but also indicates a 2.5 decline in the dust production rate between these two periods. Dynamical dust modeling shows that the coma's morphology as imaged by JWST's NIRCam instrument on 2023 November 22 can be reproduced by asymmetric dust emission from a nucleus with a midrange obliquity ( 80) with a steady-state mass-loss rate of 0.8 kg s¹. Finally, we find similar Af -to-gas ratios of for 358P and for 238P, suggesting that Af could serve as an effective proxy for estimating water production rates in other active main-belt comets. The confirmation of water vapor outgassing in both main-belt comets observed by JWST to date reinforces the use of recurrent activity near perihelion as an indicator of sublimation-driven activity in active asteroids.

18. Faga, L., Andrade-Oliveira, F., Camacho, H., Rosenfeld, R., Lima, M., Doux, C., Fang, X., Prat, J., Porredon, A., Aguena, M., Alarcon, A., Allam, S., Alves, O., Amon, A., Avila, S., Bacon, D., Bechtol, K., Becker, M., Bernstein, G., Blazek, J., Bocquet, S., Brooks, D., Buckley-Geer, E., Campos, A., Carnero Rosell, A., Carrasco Kind, M., Carretero, J., Castander, F., Cawthon, R., Chang, C., Chen, R., Choi, A., Cordero, J., Crocce, M., da Costa, L., Pereira, M., DeRose, J., Diehl, H., Dodelson, S., Drlica-Wagner, A., Elvin-Poole, J., Everett, S., Ferrero, I., Ferte, A., Flaugher, B., Fosalba, P., Frieman, J., Garcia-Bellido, J., Gatti, M., Gaztanaga, E., Giannini, G., Gruen, D., Gruendl, R., Gutierrez, G., Harrison, I., Hinton, S., Hollowood, D., Honscheid, K., Huterer, D., James, D., Jarvis, M., Jeltema, T., Kuehn, K., Lahav, O., Lee, S., Lidman, C., MacCrann, N., Marshall, J., McCullough, J., Mena-Fernandez, J., Miquel, R., Myles, J., Navarro-Alsina, A., Palmese, A., Pandey, S., Paterno, M., Pieres, A., Plazas Malagon, A., Raveri, M., Rodriguez-Monroy, M., Rollins, R., Ross, A., Rykoff, E., Samuroff, S., Sanchez, C., Sanchez, E., Sanchez Cid, D., Schubnell, M., Secco, L., Sevilla-Noarbe, I., Sheldon, E., Shin, T., Smith, M., Soares-Santos, M., Suchyta, E., Swanson, M., Tarle, G., Thomas, D., Troxel, M., Tucker, B., Tutusaus, I., Weaverdyck, N., Wiseman, P., Yanny, B., Yin, B., DES Collaboration, 2025, MNRAS, 536, 1586, Dark energy survey year 3 results: cosmology from galaxy clustering and galaxy-galaxy lensing in harmonic space
    Abstract

    We present the joint tomographic analysis of galaxy-galaxy lensing and galaxy clustering in harmonic space (HS), using galaxy catalogues from the first three years of observations by the Dark Energy Survey (DES Y3). We utilize the REDMAGIC and MAGLIM catalogues as lens galaxies and the METACALIBRATION catalogue as source galaxies. The measurements of angular power spectra are performed using the pseudo-$C_\ell$ method, and our theoretical modelling follows the fiducial analyses performed by DES Y3 in configuration space, accounting for galaxy bias, intrinsic alignments, magnification bias, shear magnification bias and photometric redshift uncertainties. We explore different approaches for scale cuts based on non-linear galaxy bias and baryonic effects contamination. Our fiducial covariance matrix is computed analytically, accounting for mask geometry in the Gaussian term, and including non-Gaussian contributions and super-sample covariance terms. To validate our HS pipelines and covariance matrix, we used a suite of 1800 log-normal simulations. We also perform a series of stress tests to gauge the robustness of our HS analysis. In the $\Lambda$CDM model, the clustering amplitude $S_8 =\sigma _8(\Omega _m/0.3)^{0.5}$ is constrained to $S_8 = 0.704\pm 0.029$ and $S_8 = 0.753\pm 0.024$ (68 per cent C.L.) for the REDMAGIC and MAGLIM catalogues, respectively. For the wCDM, the dark energy equation of state is constrained to $w = -1.28 \pm 0.29$ and $w = -1.26^{+0.34}_{-0.27}$, for REDMAGIC and MAGLIM catalogues, respectively. These results are compatible with the corresponding DES Y3 results in configuration space and pave the way for HS analyses using the DES Y6 data.

19. Chen, R., Scolnic, D., Vincenzi, M., Rykoff, E., Myles, J., Kessler, R., Popovic, B., Sako, M., Smith, M., Armstrong, P., Brout, D., Davis, T., Galbany, L., Lee, J., Lidman, C., Moller, A., Sanchez, B., Sullivan, M., Qu, H., Wiseman, P., Abbott, T., Aguena, M., Allam, S., Alves, O., Andrade-Oliveira, F., Annis, J., Bacon, D., Brooks, D., Carnero Rosell, A., Carretero, J., Choi, A., Conselice, C., da Costa, L., Pereira, M., Diehl, H., Doel, P., Everett, S., Ferrero, I., Flaugher, B., Frieman, J., Garcia-Bellido, J., Gatti, M., Gaztanaga, E., Giannini, G., Gruen, D., Gruendl, R., Gutierrez, G., Herner, K., Hinton, S., Hollowood, D., Honscheid, K., Huterer, D., James, D., Kuehn, K., Lewis, G., Lima, M., Marshall, J., Mena-Fernandez, J., Menanteau, F., Miquel, R., Ogando, R., Palmese, A., Pieres, A., Plazas Malagon, A., Roodman, A., Samuroff, S., Sanchez, E., Sanchez Cid, D., Sevilla-Noarbe, I., Suchyta, E., Swanson, M., Tarle, G., To, C., Tucker, D., Vikram, V., Weaverdyck, N., Weller, J., DES Collaboration, 2025, MNRAS, 536, 1948, Evaluating cosmological biases using photometric redshifts for Type Ia Supernova cosmology with the Dark Energy Survey Supernova Program
    Abstract

    Cosmological analyses with Type Ia Supernovae (SNe Ia) have traditionally been reliant on spectroscopy for both classifying the type of supernova and obtaining reliable redshifts to measure the distance-redshift relation. While obtaining a host-galaxy spectroscopic redshift for most SNe is feasible for small-area transient surveys, it will be too resource intensive for upcoming large-area surveys such as the Vera Rubin Observatory Legacy Survey of Space and Time, which will observe on the order of millions of SNe. Here, we use data from the Dark Energy Survey (DES) to address this problem with photometric redshifts (photo-z) inferred directly from the SN light curve in combination with Gaussian and full $p(z)$ priors from host-galaxy photo-z estimates. Using the DES 5-yr photometrically classified SN sample, we consider several photo-z algorithms as host-galaxy photo-z priors, including the Self-Organizing Map redshifts (SOMPZ), Bayesian Photometric Redshifts (BPZ), and Directional-Neighbourhood Fitting (DNF) redshift estimates employed in the DES 3 2 point analyses. With detailed catalogue-level simulations of the DES 5-yr sample, we find that the simulated w can be recovered within $\pm 0.02$ when using SN+SOMPZ or DNF prior photo-z, smaller than the average statistical uncertainty for these samples of 0.03. With data, we obtain biases in w consistent with simulations within ${\sim} 1\sigma$ for three of the five photo-z variants. We further evaluate how photo-z systematics interplay with photometric classification and find classification introduces a subdominant systematic component. This work lays the foundation for next-generation fully photometric SNe Ia cosmological analyses.

20. Kutra, T., Prato, L., Tofflemire, B., Akeson, R., Schaefer, G., Tang, S., Segura-Cox, D., Johns-Krull, C., Kraus, A., Andrews, S., Jensen, E., 2025, AJ, 169, 20, Sites of Planet Formation in Binary Systems. II. Double the Disks in DF Tau
    Abstract

    This article presents the latest results of our Atacama Large Millimeter/submillimeter Array (ALMA) program to study circumstellar disk characteristics as a function of orbital and stellar properties in a sample of young binary star systems known to host at least one disk. Optical and infrared observations of the eccentric, 48 yr period binary DF Tau indicated the presence of only one disk around the brighter component. However, our 1.3 mm ALMA thermal continuum maps show two nearly equal-brightness components in this system. We present these observations within the context of updated stellar and orbital properties, which indicate that the inner disk of the secondary is absent. Because the two stars likely formed together, with the same composition, in the same environment, and at the same time, we expect their disks to be co-eval. However the absence of an inner disk around the secondary suggests uneven dissipation. We consider several processes that have the potential to accelerate inner disk evolution. Rapid inner disk dissipation has important implications for planet formation, particularly in the terrestrial-planet-forming region.

21. Shah, P., Davis, T., Vincenzi, M., Armstrong, P., Brout, D., Camilleri, R., Galbany, L., Garcia-Bellido, J., Gill, M., Lahav, O., Lee, J., Lidman, C., Moller, A., Sako, M., Sanchez, B., Sullivan, M., Whiteway, L., Wiseman, P., Allam, S., Aguena, M., Bocquet, S., Brooks, D., Burke, D., Carnero Rosell, A., da Costa, L., Pereira, M., Desai, S., Dodelson, S., Doel, P., Ferrero, I., Flaugher, B., Frieman, J., Gaztanaga, E., Gruen, D., Gruendl, R., Gutierrez, G., 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., Pieres, A., Plazas Malagon, A., Roodman, A., Samuroff, S., Sanchez, E., Sevilla-Noarbe, I., Smith, M., Suchyta, E., Swanson, M., Tarle, G., To, C., Vikram, V., Weaverdyck, N., 2025, MNRAS, 536, 946, Constraints on compact objects from the Dark Energy Survey 5-yr supernova sample
    Abstract

    Gravitational lensing magnification of Type Ia supernovae (SNe Ia) allows information to be obtained about the distribution of matter on small scales. In this paper, we derive limits on the fraction $\alpha$ of the total matter density in compact objects (which comprise stars, stellar remnants, small stellar groupings, and primordial black holes) of mass M > 0.03 ${\rm M}_{\odot }$ over cosmological distances. Using 1532 SNe Ia from the Dark Energy Survey Year 5 sample (DES-SN5YR) combined with a Bayesian prior for the absolute magnitude M, we obtain < 0.12 at the 95 per cent confidence level after marginalization over cosmological parameters, lensing due to large-scale structure, and intrinsic non-Gaussianity. Similar results are obtained using priors from the cosmic microwave background, baryon acoustic oscillations, and galaxy weak lensing, indicating our results do not depend on the background cosmology. We argue our constraints are likely to be conservative (in the sense of the values we quote being higher than the truth), but discuss scenarios in which they could be weakened by systematics of the order of $\Delta \alpha \sim 0.04$.

21 publications and 44 citations in 2025.

21 publications and 44 citations total.