Sazuna/UAT_keywords huggingface dataset:
Deep DECam Y-band Follow-up of WISEA J153429.75-104303.3 (a.k.a. "The Accident"). WISEA J153429.75-104303.3 (a.k.a. "The Accident") is a brown dwarf with unique observational properties unlike those of any other known (sub)stellar object. It is thought to be a very cold, metal-poor brown dwarf, and potentially the first identified Y-type subdwarf. Although WISEA J153429.75-104303.3 is extremely faint at λ ~ 1.25 μm, low-temperature atmosphere models suggest that Y-band flux could increase dramatically relative to J-band as metallicity decreases from solar. We therefore obtained deep Y-band follow-up imaging of WISEA J153429.75-104303.3 with the Dark Energy Camera, and report a resulting Y-band limit of Y &gt; 21.79 mag (Vega, 5σ).

Keywords: Metallicity, Y dwarfs, T dwarfs
New Determinations of the Surface Abundances of HD 1909: Paper II: From Calcium to Mercury. New abundances for the elements calcium to mercury are measured for the brightest member of the spectroscopic binary HD 1909 using updated atomic data and spectrum synthesis. Manganese is overabundant by a unusually high factor (80 ⊙). While strontium is underabundant, yttrium and zirconium are very overabundant by factors of 250 and 500 times the solar abundances. Barium is overabundant by a factor of 20. The strongest lines of the twice ionized lanthanides Pr III and Nd III are not present which suggests the abundances of these two elements are solar or less. The Hg II line at 3983.93 Å is unusually strong and reproduced by a mercury overabundance of a factor of 500,000 times the solar mercury abundance.

Keywords: Mercury-manganese stars, Chemically peculiar stars
JWST-MIRI Synthetic Photometry Composition using 460 Spitzer-IRS Spectra of Nearby Galaxies. We use extragalactic Spitzer-InfraRed Spectrograph (IRS) spectroscopy to determine the polycyclic aromatic hydrocarbon band, emission line, and stellar and dust continuum contributions to the James Webb Space Telescope (JWST)-Mid-InfraRed Instrument (MIRI) photometric filters, F560W through F1280W, appropriate for z ~ 0 star-forming galaxies. Our data set consists of 460 IRS-SL spectra from 5.25 to 14.8 μm. Of these, 340 are from large radial strips that sample a wide range of environments across three nearby galaxies. We also include 120 spectra from the Spitzer Infrared Nearby Galaxy Survey that are centered on the brightest star-forming regions in 46 nearby galaxies. This large compilation of extragalactic mid-infrared spectra facilitates the interpretation of future work with JWST-MIRI photometry of galaxies.

Keywords: Dust continuum emission, Polycyclic aromatic hydrocarbons, Infrared spectroscopy, Infrared photometry
MPS-ATLAS Library of Stellar Model Atmospheres and Spectra. Stellar spectra contain a large amount of information about the conditions in stellar atmospheres. However, extracting this information is challenging and demands comprehensive numerical modeling. Here, we present stellar spectra synthesized using the recently developed state-of-the-art MPS-ATLAS code on a fine grid of stellar fundamental parameters. These calculations have been extensively validated against solar and stellar observations and can be used for various astrophysical applications. The spectra are available at the Max Planck Digital Library (https://doi.org/10.17617/3.NJ56TR) and have been also incorporated into the ExoTiC-LD python package (https://github.com/Exo-TiC/ExoTiC-LD/ which returns stellar limb darkening coefficients used for the software package Exoplanet Timeseries Characterisation (ExoTic).

Keywords: Stellar photospheres, Stellar atmospheres
The Behavior of BpSi Stars in the Far UV-Paper I: HD 22920. The analysis of five spectra of the Bp Si star HD 22920 recorded by the SWP camera on board the International Ultraviolet Explorer reveals variations of the far-ultraviolet flux of this star throughout its recently derived rotation period of 3.947 days. Spectra separated by half of the rotation period show variations of the FUV flux shortwards of 1700 Å. The Si II autoionization lines in the region 1350 to 1460 Å clearly vary in phase with the Si II doublet near 1530 Å. The FUV variations are caused by variations of the FUV Si II continuous and line opacity as spots of overabundant silicon come into the line of sight while the star rotates.

Keywords: Bp stars, Chemically peculiar stars
No MSP Counterparts Detected in GBT Searches of Spider Candidates 4FGL J0935.3+0901, 4FGL J1627.7+3219, and 4FGL J2212.4+0708. We performed radio searches for the "spider" millisecond pulsar (MSP) candidates 4FGL J0935.3+0901, 4FGL J1627.7+3219, and 4FGL J2212.4+0708 using the Green Bank Telescope in an attempt to detect the proposed radio counterpart of the multi-wavelength variability seen in each system. We observed using the VEGAS spectrometer, centered predominantly at 2165 MHz; however, we were also granted observations at 820 MHz for 4FGL J1627.7+3219. We performed acceleration searches on each data set using PRESTO as well as additional jerk searches of select observations. We see no evidence of a radio counterpart in any of the observations for each of the three systems at this time. Additional observations, perhaps at different orbital phases (e.g., inferior conjunction), may yield detections of an MSP in the future. Therefore, we urge continued monitoring of these systems to fully characterize the radio nature, however faint or variable, of each system.

Keywords: Millisecond pulsars
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.

Keywords: Comet tails, Hilda group, Asteroids, Comae
Interstellar Objects from Broken Dyson Spheres. Without extensive maintenance, Dyson spheres inevitably disintegrate by asteroid impacts over billions of years. The resulting fragments would appear as anomalous interstellar objects, potentially sharing the unusual shape and motion of 1I/'Oumuamua or the unusual material strength of the first two interstellar meteors, IM1 and IM2. If the Dyson sphere's tiles are light sails, the number of fragments could exceed that of interstellar asteroids because of their reduced escape speed from the star and the increase in stellar luminosity during the red giant phase.

Keywords: Asteroids, Asteroid dynamics
Tracking of the C/2022 E3 (ZTF) from Trivandrum Observatory. Established in 1837, the Trivandrum observatory has been working over the past 185 yr as an institution catering to the scientific and academic community. After a major renovation recently, the arrival of the comet C/2022 E3 (ZTF) has provided an opportunity for the Trivandrum observatory to explore its capability in astronomy. The sky remained clear from February 13th onwards for 5 days, providing a much awaited window for tracking of the path of the comet. An apparent change in the coma is visualized in the images which could be associated with the increase in the radial distance from the Earth and also due to the increase in distance from the Sun.

Keywords: Comets
Recent Updates of Gas-phase Chemical Reactions and Molecular Lines of SiS in CLOUDY. Here we present our current update of CLOUDY on gas-phase chemical reactions for the formation and destruction of the SiS molecule, its energy levels, and collisional rate coefficients with H2, H, and He over a wide range of temperatures. As a result, henceforth the spectral synthesis code CLOUDY predicts SiS line intensities and column densities for various astrophysical environments.

Keywords: Molecular physics, Interstellar medium
The Behavior of BpSi Stars in the Far UV-Paper II: HD 9996 (HR 465). The analysis of IUE spectra of the B9 SiCrEu star HD 9996 recorded by the SWP and the LWP camera on board the International Ultraviolet Explorer collected at two phases of its very long rotational period (separated by Δϕ = 0.40), reveals large variations of the far and mid ultraviolet flux. The FUV flux seems to vary in opposition with the optical brightness recorded by the Fine Error Sensor near the V band. At ultraviolet maximum, the lines of Mg II, Cr II and Fe II are definitely stronger than at minimum, which suggests that these elements are distributed in a non uniform manner on the stellar disk with large horizontal gradients. However, the changing aspect of the magnetic field between the two rotational phases observed could also cause part of the ultraviolet variability.

Keywords: Bp stars, Chemically peculiar stars
New Determinations of the Surface Abundances of HD 1280. New abundances for several chemical elements are measured for HD 1280 using updated atomic data and spectrum synthesis. The abundances of calcium and scandium are solar whereas strontium is mildly overabundant. The abundances of helium, magnesium, titanium, chromium, manganese, iron and barium are in good agreement with a former abundance analysis. This reinforces the status of HD 1280 as a normal rapidly rotating A star with essentially normal abundances of elements lighter than iron and mild overabundances of heavier elements which may actually have been present in the environment where the star was born.

Keywords: Am stars, A stars
Possible Disintegration of Main-belt Asteroid 2008 BJ<SUB>22</SUB>. Active asteroids are a mysterious population of objects on asteroid-like orbits that display comet-like activity produced by a diverse variety of mechanisms, providing glimpses of the ongoing evolution of the asteroid belt and near-Earth objects. We report the identification of a new active asteroid 2008 BJ22, from images obtained by the Subaru Telescope in 2008. The object was not detected in earlier Canada-France-Hawaii Telescope images obtained in 2005 down to a 3σ limiting magnitude of m  r  ~ 24, corresponding to a V-band absolute magnitude of H  V  &gt; 18.4, more than 3 mag fainter than the absolute magnitude computed from 2008 data. Analysis of later images obtained by the Dark Energy Camera on the 4.0 m Victor M. Blanco Telescope in 2013 set the object's current V-band absolute magnitude at H  V  &gt; 19.3. These results suggest that 2008 BJ22 was discovered in an active state in 2008 January.

Keywords: Asteroid belt, Comets, Main-belt comets
The Behavior of Bp He-weak Stars in the Far UV-Paper 2: HD 125823. The analysis of seventeen spectra of the Bp He-weak star HD 125823 recorded by the SWP camera on board the International Ultraviolet Explorer reveals no variations of the far-ultraviolet spectral energy distribution of this star over a time interval of three years. However line variations are present in the range 1400 up to 1600 Å which can be partly attributed to variations of lines of Si II and Si III. This confirms that silicon is not distributed in a uniform manner over the surface but the horizontal gradients of the silicon abundance are probably not large.

Keywords: Helium-weak stars, Chemically peculiar stars
Resolved Binaries with Late-M and L Dwarf Companions Identified in Gaia eDR3. We present a curated sample of 6688 resolved binaries containing M and L dwarf companions within 400 pc of the Sun, including 121 systems within 100 pc. These sources were selected from the Gaia EDR3 compilation of El-Badry et al., and further vetted using photometric and astrometric data from SDSS, Pan-STARRS, 2MASS, UKIDSS, and WISE, as well as visual examination of imaged fields. Only 13% of these systems were reported as co-moving pairs prior to Gaia, and only 4% of the primaries and 1% of the secondaries have published spectral classifications, including just 9 of 109 late-M and L dwarf secondaries within 100 pc. Follow-up of this expanded low-mass companion sample will provide valuable benchmark systems for precisely calibrating empirical diagnostics of the physical properties of the lowest-mass stars and brown dwarfs.

Keywords: M dwarf stars, Binary stars, Surveys, L dwarfs, Companion stars
Toward Discovery of Gravitationally Lensed Explosive Transients: The Brightest Galaxies in Massive Galaxy Clusters from Planck-SZ2. We combine the Planck-SZ2 galaxy cluster catalog with near-infrared photometry of galaxies from the VISTA Hemisphere Survey to identify candidate brightest cluster galaxies (BCGs) in 306 massive clusters in the Southern skies at redshifts of z &gt; 0.1. We find that 91% of these clusters have at least one candidate BCG within the 95% confidence interval on the cluster centers quoted by the Planck collaboration, providing reassurance that our analyses are statistically compatible, and find 92% to be reasonable candidates following a manual inspection. We make our catalog publicly available to assist colleagues interested in multi-wavelength studies of cluster cores, and the search for gravitationally lensed explosive transients in upcoming surveys including the Legacy Survey of Space and Time by the Vera C. Rubin Observatory.

Keywords: Galaxy clusters, Brightest cluster galaxies, Strong gravitational lensing, Galaxies
First Ejection from the PSR B1259-63/LS 2883 High Mass Gamma-Ray Binary Detected During the 2021-2024 Binary Cycle. LS 2883/PSR B1259-63 is a high mass, eccentric gamma-ray binary that has previously been observed to eject X-ray emitting material. We report the results of recent Chandra observations near binary apastron in which a new X-ray emitting clump of matter was detected. The clump has a high projected velocity of v ⊥ ≈ 0.07c and hard X-ray spectrum, which fits an absorbed power-law model with Γ = 1.1 ± 0.3. Although clumps with similar velocities and spectra were detected in some of the previous binary cycles, no resolved clumps were seen near apastron in the preceding cycle of 2017-2021.

Keywords: Neutron stars, High mass x-ray binary stars, Pulsars
Secondary School Students observe Venus with NASA Infrared Telescope Facility (IRTF). Astronomy and astrophysics are regarded as highly motivating topics for students in primary and secondary schools, and they have been a recurrent and effective resource to inspire passion about science. In fact, during the last years we have witnessed a boost of facilities providing small robotic telescopes for teachers and students to remotely undertake their own observing projects. A step forward is presented here, where we describe the experience of secondary school students attending professional observations of Venus at NASA's Infrared Telescope Facility and, in a second observing run, conducting the observations by themselves. In addition to quickly mastering the basic operation of the control software for the SpeX instrument, the students successfully performed different types of data acquisition, including drift scan imaging.

Keywords: Observational astronomy, Atmospheric clouds, Astronomy education, Venus, Planetary atmospheres, Astronomical techniques, Direct imaging, Infrared observatories, Drift scan imaging
A Catalog of Exoplanet Atmospheric Retrieval Codes. Exoplanet atmospheric retrieval is a computational technique widely used to infer properties of planetary atmospheres from remote spectroscopic observations. Retrieval codes typically employ Bayesian sampling algorithms or machine learning approaches to explore the range of atmospheric properties (e.g., chemical composition, temperature structure, aerosols) compatible with an observed spectrum. However, despite the wide adoption of exoplanet retrieval techniques, there is currently no systematic summary of exoplanet retrieval codes in the literature. Here, we provide a catalog of the atmospheric retrieval codes published to date, alongside links to their respective code repositories where available. Our catalog will be continuously updated via a Zenodo archive.

Keywords: Bayesian statistics, Astronomy data analysis, Exoplanet atmospheres, Spectroscopy
Bio-techno-signature Monitoring and Communication Guideposts for Extraterrestrial Life. Attendees at the First Penn State SETI Symposium collaborated to develop guideposts for monitoring for and communicating with extraterrestrial life. Over the course of six hours of moderated, dialogic, art-based inquiry in 2022 June, four foundational questions catalyzed the creation of a set of ethics-informed guideposts: Who speaks for Earth, and who should speak for Earth?; What can be communicated, and what is communicated?; What should be communicated?; and How can it be communicated? The 10 resulting parameters offer ethical navigation for examining bio- and techno-markers.

Keywords: Detection, Search for extraterrestrial intelligence
Observations of GRB 230307A by TESS. We present the Transiting Exoplanet Survey Satellite (TESS) light curve of GRB 230307A. We find two distinct components: a bright, prompt optical component at the time of the Fermi observation that peaked at TESS magnitude 14.49 ± 0.05 (averaged over 200 s), followed by a gradual rise and fall over 0.5 day, likely associated with the afterglow, that peaked at 17.65 ± 0.06 mag. The prompt component is observed in a single 200 s Full Frame Image and was undetectable in the next TESS image (T mag &gt; 17.79). Assuming that the onset of the optical transient was coincident with the gamma-ray emission, the prompt emission lasted less than 73.6 s, which implies the true peak was actually brighter than T mag = 13.40. We also fit parametric models to the afterglow to characterize its shape. The TESS TICA light curve can be retrieved at https://tess.mit.edu/public/tesstransients/light_curves/lc_grb230307A_cleaned.txt.

Keywords: Gamma-ray bursts, Gamma-ray transient sources
Repeating Outbursts from the Young Stellar Object Gaia23bab (=SPICY 97589). The light curve of Gaia23bab (=SPICY 97589) shows two significant (ΔG &gt; 2 mag) brightening events, one in 2017 and an ongoing event starting in 2022. The source's quiescent spectral energy distribution indicates an embedded (A  V  &gt; 5 mag) pre-main-sequence star, with optical accretion emission and mid-infrared disk emission. This characterization is supported by the source's membership in an embedded cluster in the star-forming cloud DOBASHI 1604 at a distance of 900 ± 45 pc. Thus, the brightening events are probable accretion outbursts, likely of EX Lup-type.

Keywords: Optical bursts, Young stellar objects, Gaia
The Behavior of Bp Si Stars in the far-UV-Paper III: HD 112413. The analysis of eleven spectra of the SiEuCr star HD 112413 recorded by the SWP camera on board the International Ultraviolet Explorer reveals variations of the far-ultraviolet spectral energy distribution over a time interval of three days and five hours. Large variations are present shortwards of 2000 Å which can be partly attributed to variations of the lines and continuum of Si II. This confirms that silicon and iron-peak elements are not distributed in a uniform manner over the surface. The FUV variations occur in antiphase with the variations of the optical brightness which probably reflects redistribution of the FUV flux toward optical wavelengths as the star rotates.

Keywords: Bp stars, Chemically peculiar stars
Magneto-convective Modeling of Low-mass Pre-main Sequence Stars: Postponing the Depletion of Lithium. Standard evolutionary models of pre-main sequence (PMS) low-mass stars often predict radii R and Li abundances A(7Li) which are too small to agree with empirical data, while effective temperatures T eff are predicted to be too large. There are also discrepancies in replicating the stellar age. Discrepancies in R, T eff, and A(7Li) are reported by Stassun et al. for both components (A/B) of the eclipsing binary 2M1222-57 belonging to the young Lower Centaurus Crux association. Using the output of a magneto-convective stellar evolution model which we applied in an early study (in 2010) of PMS stars in a different young association, we show that the discrepancies reported by Stassun et al. in the 2M1222-57 system are alleviated. The models are instructive in showing why larger lithium abundances occur in magnetic PMS stars: it takes longer for the central gas in such a star to become hot enough to destroy lithium.

Keywords: M dwarf stars, Magnetic variable stars
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.

Keywords: Comet tails, Asteroid belt, Asteroids, Comae
The Behavior of Bp Si Stars in the Far UV-Paper IV: HD 133029. The analysis of nine spectra of the Bp SiSrCr star HD 133029 recorded by the SWP camera on board the International Ultraviolet Explorer reveals variations of the far-ultraviolet spectral energy distribution over a time interval of four days and four hours. Variations are present shortwards of 1700 Å which can be partly attributed to variations of lines and continuum of Si II, Cr II and Fe II. This suggests that these elements are not distributed in a uniform manner over the stellar surface. The FUV variations occur in antiphase with the variations of the optical brightness which probably reflects redistribution of the FUV flux toward optical wavelengths as the star rotates.

Keywords: Bp stars, Chemically peculiar stars
Recent Extragalactic Nova Rate Determinations and their Implications. Comparing the rates of novae in galaxies of differing Hubble types reveals the sensitivity of nova eruptions to the properties (age, star formation history, metallicity) of the underlying stellar population. Recent studies using the Hubble Space Telescope have suggested that earlier ground-based surveys may have underestimated extragalactic nova rates by factors of five or more. Here we discuss the implications of such high specific nova rates on nova theory in general, and on the chemical evolution of galaxies, including the Milky Way, in particular.

Keywords: Galaxy chemical evolution, Novae
The Behavior of Bp He-weak Stars in the Far UV-Paper III: HD 175362. The analysis of twelve spectra of the Bp He-weak Si star HD 175362 recorded by the SWP camera on board the International Ultraviolet Explorer reveals variations of the far-ultraviolet spectral energy distribution over a time interval of several years. Variations are present shortwards of 1700 Å which can be partly attributed to variations of lines and continuum of Si II. Other lines due to C II, Si III and Si IV also contribute to the opacity in this range too. The variations suggest that silicon and carbon are not distributed in a uniform manner over the surface.

Keywords: Helium-weak stars, Chemically peculiar stars