Sazuna/UAT_keywords huggingface dataset:
Two Nested Shells around the Blue Supergiant ALS 19653. We present the results of deep narrowband imaging of two nested shells around the blue supergiant ALS 19653, which confirm that the outer shell is physically associated with the star.

Keywords: Circumstellar matter, B supergiant stars
Detection of the Occultation of 55 Cancri e with TESS. 55 Cancri e is an ultra-short period transiting Super-Earth observed by TESS in Sector 21. Using this photometry, we measure the occultation depth in the TESS bandpass, leveraging the precise transit light curve and comparing multiple detrending methods. We measure the occultation depth to be (15.0 ± 4.8) ppm—a staggeringly small change in brightness, yet one detected by TESS in just a single sector of data. This implies a brightness temperature of ${2800}_{-160}^{+130}$ K, which is around 1.5σ greater than expected given the mean depth measured with Spitzer. This is not a formally significant difference, and may be accounted for by the known variability, or by an albedo of ∼0.5. In any case, future TESS observations of this system will provide an exciting opportunity to further study this diminutive world's atmosphere.

Keywords: Exoplanet astronomy, Exoplanet atmospheres
Identification of Orbital Eclipses in LAMOST J024048.51+195226.9, a Candidate AE Aqr-type Cataclysmic Variable Star. AE Aqr objects are a class of cataclysmic variable stars in which the rapidly rotating magnetosphere of the white dwarf (WD) primary centrifugally expels most infalling gas before it can accrete onto the WD. The expulsion of the accretion flow via this "magnetic propeller" extracts angular momentum from the WD and produces large-amplitude, aperiodic flares in optical photometry. The eponymous AE Aqr is the only confirmed member of this class of object, but recently, Thorstensen discovered a candidate AE Aqr system: LAMOST J024048.51+195226.9. Using survey photometry, we measure a refined orbital period for this system and identify a shallow, previously unrecognized eclipse during which the system's frequent AE Aqr-like flaring episodes cease. A dedicated follow-up study is still necessary to test the proposed AE Aqr classification for LAMOST J024048.51+195226.9, but should it be confirmed, the eclipse of its flare-production region will offer a new means of studying the magnetic propeller phenomenon.

Keywords: DQ Herculis stars, Cataclysmic variable stars, White dwarf stars
CNO Cycle Burning in Ultra-low Metallicity Solar Mass Stars. We use the 1D stellar evolution code MESA to run select models at one solar mass at near zero metallicity to examine the effect of a lack of catalysts for CNO burning on the evolution of these models. We find that for metallicities below 10-10 ${Z}_{\odot }$ a loop occurs on the HR diagram as the star evolves off the main sequence, corresponding to the onset of significant CNO burning in the core of the star. This feature is visible in the Kippenhahn diagram as a period where the core becomes convective while the burning takes place. During this loop, the degeneracy of the core is lifted as CNO burning produces around 3.7% of the total nuclear energy.

Keywords: Stellar evolutionary models, Metallicity, Carbon-nitrogen cycle
Evidence for a Buried AGN in an Extremely Bright Dusty Galaxy at z = 2. We present preliminary results of a submillimeter spectral line survey of a strongly lensed dusty star-forming galaxy (DSFG) at z ∼ 2, near the peak epoch of cosmic star formation. We use data from the Submillimeter Array, which recently completed a systems upgrade that substantially increased the instantaneous bandwidth. Focusing on the brightest spectral lines of CO and atomic carbon, we characterize the interstellar medium properties of this galaxy. We find highly excited CO and [C I] emission, and a large [C I] line ratio implies a higher excitation temperature than other extreme high-redshift sources. Based on this evidence, we infer that the source likely hosts a dust-obscured active galactic nucleus similar to other well-studied DSFGs.

Keywords: Starburst galaxies, Spectral line identification, Active galactic nuclei, CO line emission, Submillimeter astronomy, Radio astronomy, High-redshift galaxies, Galaxies, Interferometry
A Catalog of Very Large Array Sky Survey Epoch 1 Quick Look Components, Sources, and Host Identifications. We announce here the public availability of a catalog of ν ∼ 3 GHz Quick Look observations from the first epoch of the Very Large Array Sky Survey. The catalog consists of three distinct and linkable tables, namely (a) the detected radio components, (b) the host identifications with total source properties for single-component, and close double/triple radio sources (angular separations of &lt;10″), and (c) the Quick Look image metadata. Given the Quick Look images are limited in quality, we include data reliability flagging to improve the scientific usability of this catalog. Using our recommended quality flags, this catalog contains 1.7 × 106 unique radio components with S3 GHz ≳ 1 mJy beam-1, and 6.2 × 105 host IDs (including 20,000 close-double and triple radio sources) reliably detected across the entire sky at δ &gt; -40°. The catalog and an associated User Guide have been produced as part of the Canadian Initiative for Radio Astronomy Data Analysis, and are available at https://cirada.ca/catalogues.

Keywords: Radio astronomy, Sky surveys, Radio source catalogs
Spectroscopic Classification of Six Cataclysmic Variables with the Liverpool Telescope. This paper presents classification spectroscopy of 6 cataclysmic variables obtained with the Liverpool Telescope. These objects were discovered and identified as likely dwarf novae by the Gaia Alerts or ASAS-SN transient surveys.

Keywords: Cataclysmic variable stars, Dwarf novae
A Layered Approach to Robust Determination of Asteroseismic Parameters. We describe here a layered approach to the robust determination of the broad characteristics of the asteroseismic signal from red-giant stars. No single stringent test can exclude all false results. The use of multiple, weak tests not only provides robust results but also avoids over-constraining the parameter space.

Keywords: Software documentation, Asteroseismology
Detector Count Rate Nonlinearity Determination Using Signal Intermodulation. Detectors that use HgCdTe exhibit Count Rate Non-Linearity (CRNL), where the integrated photon-generated charge in a pixel has an undesirable variation with photon arrival rate, at fixed delivered photon dose. Correcting for this is essential to meet the science goals of the Roman Space Telescope. The CRNL effect is distinct from signal-level-dependent (but photon-rate-independent) nonlinearity. We describe a potential method for measuring CRNL, by illuminating the sensor with two modulated light sources running at different frequencies, f1 and f2. The CRNL-modified generation of photocharge in the material produces a variation in the accumulated charge versus time with Fourier components at the beat frequencies (f1 - f2) and (f1 + f2). Successive non-destructive read-up-the-ramp measurements could perhaps be used to quantify CRNL, and distinguish it from nonlinearities in the downstream electronics. A pair of LEDs driven with square waves at different frequencies are appropriate sources.

Keywords: Astronomical detectors, Flux calibration
Preliminary Target Selection for the DESI Quasar (QSO) Sample. The DESI survey will measure large-scale structure using quasars as direct tracers of dark matter in the redshift range 0.9 &lt; z &lt; 2.1 and using quasar Lyα forests at z &gt; 2.1. We present two methods to select candidate quasars for DESI based on imaging in three optical (g, r, z) and two infrared (W1, W2) bands. The first method uses traditional color cuts and the second utilizes a machine-learning algorithm.

Keywords: Large-scale structure of the universe, Redshift surveys, Quasars
Preliminary Target Selection for the DESI Emission Line Galaxy (ELG) Sample. DESI will precisely constrain cosmic expansion and the growth of structure by collecting ∼35 million redshifts across ∼80% of cosmic history and one third of the sky to study Baryon Acoustic Oscillations (BAO) and Redshift Space Distortions (RSD). We present a preliminary target selection for an Emission Line Galaxy (ELG) sample, which will comprise about half of all DESI tracers. The selection consists of a g-band magnitude cut and a (g - r) versus (r - z) color box, which we validate using HSC/PDR2 photometric redshifts and DEEP2 spectroscopy. The ELG target density should be ∼2400 deg-2, with ∼65% of ELG redshifts reliably within a redshift range of 0.6 &lt; z &lt; 1.6. ELG targeting for DESI will be finalized during a "Survey Validation" phase.

Keywords: Observational cosmology, Redshift surveys, Emission line galaxies, Large-scale structure of the universe
Preliminary Target Selection for the DESI Luminous Red Galaxy (LRG) Sample. The DESI survey will observe more than 8 million candidate luminous red galaxies (LRGs) in the redshift range 0.3 &lt; z &lt; 1.0. Here we present a preliminary version of the DESI LRG target section developed using Legacy Surveys Data Release 8 g, r, z and W1 photometry. This selection yields a sample with a uniform surface density of ∼600 deg-2 and very low predicted stellar contamination and redshift failure rates. During DESI Survey Validation, updated versions of this selection will be tested and optimized.

Keywords: Observational cosmology, Redshift surveys, Large-scale structure of the universe
A Sky Brightness Model for the Starlink "Visorsat" Spacecraft. A model of the brightness of the "visorsat" Starlink spacecraft is presented based on published information on the engineering design and 80 observations of individual visorsats. Comments are offered on the implications of this model on the visibility of visorsat spacecraft across the sky.

Keywords: Artificial satellites, Space vehicles
Doppler Beaming of M Dwarfs in TESS, Kepler/K2, and Gaia Photometry. The Doppler beaming amplitude of a M dwarf is amplified relative to a blackbody of the same temperature because of deep TiO absorption features in M dwarf spectra. A strong Na feature at 5890 Å coincides with the short wavelength cutoff of the Transiting Exoplanet Survey Satellite response function, which also increases the beaming amplitude. As a result, the Doppler beaming effect for a 3000 K object is a factor of 1.4-2.0 times greater than predicted for a blackbody. Underestimating the Doppler beaming coefficient could result in mass overestimates when using the photometric beaming amplitude to determine stellar properties. This is especially important for M dwarfs in short period binary systems with massive white dwarf, neutron star or black hole companions.

Keywords: M dwarf stars, Binary stars, White dwarf stars, Photometry, Doppler shift
Cloudy in the Microcalorimeter Era: Improved Energies for Kα Transitions. X-ray missions with microcalorimeter technology will resolve spectral features with unprecedented detail. In this work, we improve the H-like Kα energies for elements between 6 ≤ Z ≤ 30 for the release version of the spectral simulation code Cloudy to match laboratory energies. We update the ionization potential (Iion) for these elements and add a fourth-order polynomial to the level energy difference. This brings the release version of Cloudy into a near-perfect agreement with NIST. The updated energies are ∼15-4000 times more precise than that of the current release version of Cloudy (C17.02). These new changes will be a part of the next update to the release version, C17.03.

Keywords: High resolution spectroscopy, X-ray astronomy
Retrieving Internal Kinematics of Galaxies with Deep Learning Using Single-band Optical Images. Using deep machine learning we show that the internal velocities of galaxies can be retrieved from optical images trained using 4596 systems observed with the SDSS-MaNGA survey. Using only i-band images we show that the velocity dispersions and the rotational velocities of galaxies can be measured to an accuracy of 29 km s-1 and 69 km s-1 respectively, close to the resolution limit of the spectroscopic data. This shows that galaxy structures in the optical holds important information concerning the internal properties of galaxies, and that the internal kinematics of galaxies are quantitatively reflected in their stellar light distributions.

Keywords: Galaxy structure, Convolutional neural networks, Galaxy classification systems
Future Approach Distances and Times of Gliese 710 and R Cra to the Solar System Using Gaia DR2. I present the future approach distances and times of the stars Gliese 710 and R Cra run toward the future under a global galactic model with input parameters from the Gaia repositories. I found that the star Gliese 710 will approach the Sun closer than previously estimated. These results can confirm other calculations done to find the remarkable differences between the results of models with pre-Gaia and Gaia databases.

Keywords: Stellar motion, Stellar kinematics, Solar system, Stellar dynamics, Solar neighborhood
Preliminary Target Selection for the DESI Bright Galaxy Survey (BGS). The Dark Energy Spectroscopic Instrument (DESI) will execute a nearly magnitude-limited survey of low redshift galaxies (0.05 ≤ z ≤ 0.4, median z ≈ 0.2). Clustering analyses of this Bright Galaxy Survey (BGS) will yield the most precise measurements to date of baryon acoustic oscillations and redshift-space distortions at low redshift. DESI BGS will comprise two target classes: (i) BRIGHT (r &lt; 19.5 mag), and (ii) FAINT (19.5 &lt; r &lt; 20 mag). Here we present a summary of the star-galaxy separation, and different photometric and geometrical masks, used in BGS to reduce the number of spurious targets. The selection results in a total density of ∼800 objects deg-2 for the BRIGHT and ∼600 objects deg-2 for the FAINT selections. A full characterization of the BGS selection can be found in Ruiz-Macias et al.

Keywords: Galaxies, Large-scale structure of the universe, Observational cosmology, Redshift surveys, Catalogs
Preliminary Target Selection for the DESI Milky Way Survey (MWS). The DESI Milky Way Survey (MWS) will observe ≥8 million stars between 16 &lt; r &lt; 19 mag, supplemented by observations of brighter targets under poor observing conditions. The survey will permit an accurate determination of stellar kinematics and population gradients, characterize diffuse substructure in the thick disk and stellar halo, enable the discovery of extremely metal-poor stars and other rare stellar types, and improve constraints on the Galaxy's 3D dark matter distribution from halo star kinematics. MWS will also enable a detailed characterization of the stellar populations within 100 pc of the Sun, including a complete census of white dwarfs. The target catalog from the preliminary selection described here is public (Available at https://data.desi.lbl.gov/public/ets/target/catalogs/ and detailed at https://desidatamodel.readthedocs.io).

Keywords: Stellar abundances, White dwarf stars, Spectroscopy, Radial velocity, Milky Way Galaxy
Satellite Constellation Internet Affordability and Need. Large satellite constellations in low-Earth orbit seek to be the infrastructure for global broadband Internet and other telecommunication needs. We briefly review the impacts of satellite constellations on astronomy and show that the Internet service offered by these satellites will primarily target populations where it is unaffordable, not needed, or both. The harm done by tens to hundreds of thousands of low-Earth orbit satellites to astronomy, stargazers worldwide, and the environment is not acceptable.

Keywords: Artificial satellites
Predictions for Strong-lens Detections with the Nancy Grace Roman Space Telescope. Strong gravitational lensing is an ideal tool for mapping the distribution of dark matter and for testing the values of cosmological parameters. Forthcoming surveys such as Euclid and the Rubin Observatory Large Synoptic Telescope Survey should increase the number of known strong lensing systems significantly, with for example over 100,000 such systems predicted in the Euclid wide survey. In this short research note we predict that approximately 17,000 strong gravitational lenses will also be detectable in the Nancy Grace Roman Space Telescope 2000 square degree survey, using the LensPop gravitational lensing model. We present predicted distributions in source and deflector redshifts, magnitudes, and magnifications. Although this survey is not primarily designed as a strong lensing detection experiment, it will still provide a large complementary catalog to shallower, wider-area forthcoming lensing discovery projects.

Keywords: Cosmology, Observational astronomy, Strong gravitational lensing, Infrared astronomy, Galaxy evolution
Uranus&amp;' Stratospheric HCl Upper Limit from Herschel/SPIRE. Herschel/SPIRE observations of Uranus are used to search for stratospheric hydrogen chloride (HCl) emission at 41.74 cm-1. HCl was not detected and instead 3σ upper limits were determined; &lt;6.2 ppb (&lt;2.0 × 1014 molecules cm-2) for a 0.1 mbar step profile and &lt;0.40 ppb (&lt;1.2 × 1014 molecules cm-2) for a 1 mbar step profile. HCl is expected to have an external source and these upper limits are consistent with abundances of other external species (CO, H2O, CO2) and a solar composition source. * Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Keywords: Atmospheric composition, Solar system gas giant planets, Planetary science, Uranus
Evidence That HR 6990 Is a Spectroscopic Binary Hosting a Chemically Peculiar Late B-type star. The archival IUE spectra of the late B giant HR 6990 are used to show that the absorption lines undergo large radial velocity variations in 2 spectra taken 4 months and 10 days apart. These large RV variations confirm that HR 6990 is a spectroscopic binary. The detection of strong lines of P II, Ga II, Ga III and Hg II show that the brightest member of the system, HR 6990 A, is not a normal late B-type giant but a newly discovered Chemically Peculiar star, probably a phosphorus and gallium enriched main sequence star. The two high resolution IUE spectra do not allow us to elucidate the nature of the companion, HR 6990 B.

Keywords: Spectroscopic binary stars, Chemically peculiar stars
A Photometric Hα Survey of the Open Cluster M29. Photometric B, V, R, and Hα observations of the young open cluster M29 have been used to search for emission-line stars. Four stars with prominent Hα emission are identified. One of these may be a Herbig AeBe star that shows significant variation in emission strength during the four-month observing interval.

Keywords: Young star clusters, Emission line stars
Optical Transients Found by MASTER during the Observation of LIGO/VIRGO S200219ac Gravitational-wave Event. We present the results of MASTER Global Robotic Net optical observations of the region within the LIGO/Virgo S200219ac error-box, triggered during the O3 run. We observed 1124 square degrees inside the 3σ error box during a half month. We present the identified optical transients found during this study, which are not related to gravitational waves, and briefly discuss the MASTER observation strategy.

Keywords: Sky surveys, Gravitational wave astronomy, Automatic patrol telescopes, Transient detection, LIGO
Supernova X-Ray Database (SNaX) Updated to Ensure Long-term Stability. The Supernova X-Ray Database was established a few years ago to make X-ray data on supernovae (SNe) publicly available via an elegant searchable web interface. The database has recently been updated to PhP7, had security updates done, and moved to a new server, ensuring its long-term stability. We urge astronomers to continue to download the data as needed for their work. Those with X-ray data on SNe are requested to upload it to the database via the easily fillable spreadsheet, making it accessible to everyone.

Keywords: Astronomy databases, Core-collapse supernovae, X-ray transient sources, Supernovae, Catalogs
Atmospheric Dust Causes Darkness to Fall Rapidly on Mars. On mission sol 783 (at Martian solar longitude (LS) of 217°), Mars Science Laboratory's MastCam instrument imaged a faint glow, extending upwards from the horizon (Figure 1(a)). The images were acquired from 18:58 to 19:01 LTST, nearly an hour after sunset occurred at 18:05 LTST, providing an opportunity to examine illumination in the Martian sky around sunset. The radiance of the observed glow is small when compared to daytime sky brightness values, with an average value between 20 and 35 μW m-2 Sr-1, and appears brightest in the blue filter (the average B/R ratio is 1.25). The total flux at the time of the measurement was calculated to be 4.2 × 10-4 W m-2, nearly three orders of magnitude dimmer than what would be expected for an Earth-like Atmosphere. An observer on the surface of Mars would thus find twilight becoming deeper much more rapidly than on the Earth.

Keywords: Twilight, Mars, Planetary atmospheres, Optical observation
TESS Photometry of the Precataclysmic Variable Wolf 1130AB. Wolf 1130 is a triple system containing an ultramassive white dwarf (Wolf 1130B), an M subdwarf (Wolf 1130A) and a T8 subdwarf (Wolf 1130C). We set out to determine a precise mass for Wolf 1130B by phase-folding TESS photometry to the previously reported orbital period. Each orbit was fit for ellipsoidal, Doppler beaming, and thermal photometric variability. We found that the measured beaming amplitude of Wolf 1130AB is nearly triple the theoretical expectation, which we assign to the short-wavelength filter cutoff of TESS and features in the M subdwarf spectrum. The photometric amplitudes suggest inflation of Wolf 1130A by as much as 20%, possibly due to its rapid rotation under tidal locking. TESS photometry can be used to obtain masses for short-period binary systems, but photometric precision limits the utility in the case of Wolf 1130AB.

Keywords: M dwarf stars, Subdwarf stars, Close binary stars, White dwarf stars, Photometry, Cataclysmic variable stars
An Efficient Velocity Update for the Method of Benítez-Llambay et al. (2019). We present a fast velocity update for the drag-force solver described in Benítez-Llambay et al. for N species. This velocity update is valid when drag forces between N - 1 species are negligible, a regime of particular relevance to dust dynamics in gaseous protoplanetary disks. The complexity of the solution is ${ \mathcal O }(N)$ , that is ${ \mathcal O }({N}^{2})$ faster than standard matrix inversion, enabling efficient calculations of multi-species protoplanetary disks.

Keywords: Astrophysical dust processes, Computational methods, Planet formation
Maintaining Numerical Positivity in Strong Magnetized Astrophysical Shocks. Riemann solvers play a vital role in fluid dynamics simulations. Extreme cases, however, can generate artificially negative pressures and magnetic monopoles, destabilizing the solver. Here we couple the numerical scheme of Waagan that maintains positivity with the constrained transport method to solve the magnetohydrodynamics equations. This extends the applicability of the Waagan scheme to a wider range of problems, especially with large density and pressure gradients that occur widely in astrophysical problems.

Keywords: Magnetohydrodynamics, Astrophysical fluid dynamics, Hydrodynamics