Sazuna/UAT_keywords huggingface dataset:
Hidden Companions to Intermediate-mass Stars. XVIII. Discovery of a 0.88M <SUB>⊙</SUB>, 26 au Companion to n Centauri. n Centauri is a nearby A-type star. Here we report the discovery of a companion with an H band flux ratio   $\tfrac{{f}_{{\rm{B}}}}{{f}_{{\rm{A}}}}=3.9 \% \pm 0.4 \% $   at a projected separation ρ = 570 mas ↔ 26 au based on the acquisition camera image of a VLTI/GRAVITY observation. Isochrone fitting yields masses M A = 2.07M ⊙ and M B = 0.88M ⊙ and an age of 900 Myr. The newly discovered companion explains the Δv = 2.3 ± 0.1 km s‑1 Gaia-Hipparcos proper motion change of n Cen in both direction and magnitude as well as its X-ray emission. The interferometric data excludes the presence of any additional companion to the primary with a K band flux ratio higher than 0.9% (M ≳ 0.52M ⊙ for a main sequence star) within ρ &gt; 5 mas ↔ 0.23 au. *Based on observations collected at the European Southern Observatory, Chile, Program ID 111.24UP.001.

Keywords: Optical interferometry, Multiple stars, A stars
ASKAP-EMU Discovery of "Raspberry": A New Galactic SNR Candidate G308.73+1.38. We report the Australian Square Kilometre Array Pathfinder discovery of a new Galactic supernova remnant (SNR) candidate G308.73+1.38, which we name Raspberry. This new SNR candidate has an angular size of 20.'7 × 16.'7, and we measure a total integrated flux of 407 ± 50 mJy. We estimate Raspberry's most likely diameter of 10–30 pc which would place it at a distance 3–5 kpc, in the near side of the Milky Way's Scutum–Centaurus Arm. We also find a Stokes-V point source close to the center of Raspberry with a ∼5σ significance. This point source may be the remaining compact source, a neutron star, or possibly a pulsar, formed during the initial supernova event.

Keywords: Supernova remnants, Milky Way Galaxy, Interstellar medium, Radio continuum emission
Predicting Stellar Masses of the First Galaxies Using Graph Neural Networks. Theoretical models of galaxy formation and evolution are primarily investigated through cosmological simulations and semi-analytical models. The former method consumes   ${ \mathcal O }({10}^{6})$   core-hours explicitly modeling the dynamics of the galaxies, whereas the latter method only requires   ${ \mathcal O }({10}^{3})$   core-hours foregoing directly simulating internal structure for computational efficiency. In this work, we present a proof-of-concept machine learning regression model, using a graph neural network architecture, to predict the stellar mass of high-redshift galaxies solely from their dark matter merger trees, trained from a radiation hydrodynamics cosmological simulation of the first galaxies.

Keywords: Neural networks, Stellar masses, High-redshift galaxies, Dark matter, Galaxies
The FUV Fluxes of A-type Star Members of the Hyades. The International Ultraviolet Explorer database has been searched for the FUV spectra of the A stars which are members of the Hyades. Eight out of 16 confirmed members of the Hyades have FUV absolute fluxes obtained with the SWP camera through the large aperture. The observed sharp decrease of the FUV fluxes from spectral type A2 to A9 is essentially a temperature effect. The FUV flux of the A7 IV star HD 28310, a δ Scuti star, is clearly variable.

Keywords: Main sequence stars, Chemically peculiar stars
Validating Gaia DR3 Pulsating Variable Classifications with TESS: Building Reliable δ Scuti and γ Doradus Stars Catalogs (In Progress). Gaia DR3 revealed 748,058 pulsating variable stars of mixed DSCT∣GDOR∣SXPHE types. This project undertakes a comprehensive examination to validate and distinguish these stars using Transiting Exoplanet Survey Satellite data. Aiming for reliable catalogs of bona fide δ Scuti and γ Doradus stars, I have validated 1715 δ Scuti stars, 1403 γ Doradus stars, and identified 260 eclipsing binaries, one RR Lyrae star, and 460+ rotating variables from an initial sample of 16,690 objects. Notably, 15 of the newfound eclipsing binaries harbor pulsating γ Doradus components. *Dedicated to my wife Jingyun Zhang.

Keywords: Delta Scuti variable stars, Pulsating variable stars, RR Lyrae variable stars, Eclipsing binary stars, Gamma Doradus variable stars
Forty Hypervelocity Stars from Gaia DR3. Forty hypervelocity stars (HVS) are detected from a search for HVS in Gaia DR3 data whose G magnitudes are less than 17.0 and radial velocities are more +400 km s‑1. The Gaia DR3 astrophysical parameters and spectra indicate that most of the HVS reported in this study are F, G, and K type metal-poor stars. Eleven stars are at high galactic latitudes. Included in this study are the B components of six nearby visual double stars BD-6 885B, HD 47503B, HD 53229B, HD 95123B, HD 180683B, and HD 202276B which are found to be HVS. The A components of these six visual doubles are less massive late-type stars with normal radial velocities. The source of hypervelocity of the B components is not clear. They may have less luminous and relatively massive degenerate component stars which are not yet detected. Further study of all these HVS is needed.

Keywords: Hypervelocity stars
Measuring the Chemodynamics and Ages of the M32 and M110 Dwarf Galaxies with APOGEE. We present a full-spectrum-fitting analysis of the central kinematics and chemistry of the Andromeda dwarf satellite galaxies M32 and M110. We use an Markov Chain Monte Carlo routine to fit high-resolution, near-infrared, integrated-light spectra from APOGEE with empirical simple stellar population templates constructed from individual APOGEE stellar spectra. This yields the best-fitting mean radial velocity, velocity dispersion, metallicity, α abundance, and age for each spectrum. In general, our results are consistent with literature values where available, and we explore possible reasons where offsets are measured. This study was presented in a poster at the 243rd meeting of the American Astronomical Society in 2024 January.

Keywords: Dwarf galaxies
The Hg II Line at 5677.10 Å: A New Proxy to Derive Abundances of Mercury in Late B-type Stars?. Abundance determinations of mercury in late B-type stars in the optical range usually rely on the use of one absorption line of Hg II at 3983.93 Å. A proposal is made to use another but weaker line of Hg II located at 5677.10 Å. This line is present in the spectra of two mercury rich stars, κ Cnc and HD 58661, and absent in 53 Tau whose abundance of mercury is less than the solar value. The synthesis of the 5677.10 Hg II line, using the current atomic parameters available in NIST, confirms that mercury is very abundant in κ Cnc and HD 58661. The abundances derived with 5677.10 Å are currently less than these derived from 3983.93 Å.

Keywords: Mercury-manganese stars, Chemically peculiar stars
Initial Entropy and Potential Delayed Formation of the Directly Imaged Exoplanet AF Lep b. AF Lep b is a rare directly imaged exoplanet with properties consistent with core-accretion evolution models. Using its precise dynamical mass and spectroscopically inferred bolometric luminosity alongside the Spiegel &amp; Burrows evolution models, I determined an initial entropy &gt;8.7 k  B /baryon at 3σ and an age of 12 ± 4 Myr for AF Lep b. Comparing this planet's age to the isochrone age (24 ± 3 Myr) of its host association, the β Pictoris moving group (BPMG), suggests AF Lep b formed 12 ± 5 Myr later than its host star. Alternatively, the BPMG's updated kinematic age (  ${16.3}_{-2.1}^{+3.4}$   Myr) implies that AF Lep b formed 5 ± 5 Myr after its host star's formation, aligning more closely with protoplanetary disk dispersal timescales. The sensitivities of our findings to the planet's mass and luminosity are discussed. AF Lep b uniquely facilitates the constraints of its initial entropy and formation epoch, paving the way for similar insights into forthcoming exoplanet discoveries.

Keywords: Exoplanet evolution, Exoplanet formation
Blasting off with NASA's Neurodiversity Network. NASA's Neurodiversity Network (N3) is a five-year program that is funded as part of NASA's Science Activation Network. N3's main goal is to provide a pathway to NASA participation and Science, Technology, Engineering, and Mathematics (STEM) employment for neurodiverse learners, with a focus on those on the autism spectrum. Through the N3 program, we are enabling STEM education for a segment of the population that is significantly underserved through a process in which existing NASA education resources are redesigned with significant input from autistic learners and their instructors. The co-design process occurs primarily in informal environments, including high school summer programs, and camps and activity sessions for middle school students sponsored by the New York Hall of Science. N3 also offers a mentored summer internship program for at least ten neurodiverse high school students each year. Mentoring is provided by NASA Subject Matter Experts, individuals who collectively possess expertise that spans NASA's Science Mission Directorate.

Keywords: Astronomy education, Rockets
Dual-band, Multi-aperture Polarization Measurements of β Pictoris. We present high precision, dual-band aperture polarimetry of the β Pictoris debris disk. The polarization is aperture dependent, increasing from 5″ to 19″ and peaking, after interstellar subtraction at around 230–240 ppm in both   $g^{\prime} $   and   $r^{\prime} $   bands; the polarization vector is oriented perpendicular to the disk major-axis. By simple calculations, lower limits are placed on the polarization of scattered light interior to 200 au. The observations and calculations are consistent with prior spatially resolved polarimetric measurements of the disk that probe greater angular separations, and models for the interior developed from them.

Keywords: Circumstellar dust, Debris disks, Polarimetry, Starlight polarization
Minimum Mars Climate Sounder Retrieval Altitudes Reveal Cloud Altitudes at Aphelion and Stranded High-altitude Dust Following the MY34 Global Dust Storm on Mars. The Mars Climate Sounder (MCS) has been observing Mars' atmosphere since the Mars Reconnaissance Orbiter's arrival in 2006. While MCS can theoretically observe down to the surface, in practice the presence of aerosols such as dust and water ice can cut off retrievals at altitudes tens of kilometers above the surface. We examine the minimum cut-off altitudes of MCS temperature retrievals over the course of MCS's mission for the area around Gale Crater. We see a preference for cut-off altitudes above 20 km in the cloudy season and greater variation in preference in the dusty season. These cut-off altitudes can be used to infer cloud altitudes and to track the decay of significant dust storms as well as seeing the effects of stranded dust in the MY 34 global dust storm.

Keywords: Atmospheric clouds, Mars, Planetary atmospheres, Remote sensing, Atmospheric variability
X-Ray Observations of the Zwicky 3146 Galaxy Cluster Reveal a 3.5 keV Excess. In this note, we present spectral fits of the well-documented sloshing cool-core cluster Zwicky 3146 (z = 0.291), to test the existence of the highly speculated 3.5 keV line. We report excesses at &gt;3σ significance at E = 3.575 keV, yielding a flux   $F={8.73}_{-2.22}^{+2.17}\times {10}^{-6}$   photons cm‑2 s‑1, in XMM-Newton, and E = 3.55 keV, with a flux   $F={10.0}_{-2.96}^{+3.05}\times {10}^{-6}$   photons cm‑2 s‑1 in Chandra. We explore the possibility that the 3.5 keV excess is correlated to the presence of cold gas within the cluster, based on optical and sub-mm literature analyses. Following the launch of the X-ray Imaging and Spectroscopy Mission, high resolution spectroscopy (≤7 eV) will reveal in unprecedented detail, the origin of this unidentified feature, for which Zwicky 3146 should be considered a viable target, due to the strength of the feature in two independent X-ray telescopes, opening a new window into plasma or charge exchange studies in galaxy clusters.

Keywords: Galaxy clusters, Cooling flows, X-ray telescopes, X-ray surveys, Charge exchange ionization, Intracluster medium, Dark matter
The Phenomena of Flares and CMEs in the Sun and Stars: Why Are the Energy Upper Limits in Both Phenomena Comparable?. Solar/stellar flares which release large energies occur less frequently than those with small energies. Flare energies on a given star have not (yet) been observed to exceed E  fm . Similarly, coronal mass ejections (CME's) with large kinetic energies (KE) on a given star also occur less frequently than those with small energies. The KE's of CME's on a given star have not (yet) been observed to exceed KE m . Interestingly, in any given star, E  fm  is found to be comparable in magnitude to KE m . This is puzzling since a one-to-one correlation between flares and CME's does not exist: some flares occur without any accompanying CME, and some CME's have no accompanying flare. Moreover, different types of MHD instabilities are believed to give rise to flares and CME's. The result E  fm  ≈ KE m  could indicate support for Bemporad's conclusion: magnetic energy in the corona is in global equipartition with gravitational potential energy.

Keywords: Solar flares, Stellar flares
Exogenous Carbon is Unlikely to be the Source of Methane Microseepage Emissions on Mars. A complete understanding of methane in the atmosphere of Mars requires information on putative sources. Organic carbon derived from meteoritic sources, such as interplanetary dust particles (IDPs), over geologic time is the best-defined source of organic carbon on the surface of Mars. Here we examine two different mechanisms for degrading this material to produce methane (1) Ultraviolet photolysis and (2) thermal decomposition. Neither of these mechanisms can produce sufficient methane under realistic assumptions to explain observed methane at Gale Crater, suggesting that IDPs are not the primary source material producing methane on Mars.

Keywords: Methane, Atmospheric composition, Mars, Ultraviolet photometry, Meteorites, Interplanetary dust
EVN 5 GHz e-VLBI Observations of SN2023ixf in M101. SN 2023ixf is a Type II-L supernova that occurred in M101 in 2023 May. The European VLBI Network (EVN) observed SN 2023ixf at 5 GHz approximately one month later, on June 28. We calibrated the EVN data using AIPS and CASA, reporting non-detection of a radio source with 5σ flux upper limits of 113 μJy and 135 μJy for both pipelines, respectively.

Keywords: Observational astronomy, Core-collapse supernovae, Type II supernovae, Radio astrometry, Supernovae, Interferometry
Celestial Mechanics Leading up to the AAS Division on Dynamical Astronomy. This talk reviewed key developments leading to the establishment of the AAS Division on Dynamical Astronomy. In the 1890s, Simon Newcomb calculated astronomical constants and ephemerides for solar system bodies that were internationally adopted and used for 80 yr. The introduction of punch card equipment in the 1940s and computers in the 50s allowed much faster computations. Launches of Sputnik, Explorer, Vanguard, and Mercury satellites led to computing the orbits of satellites around the Earth and the field of astrodynamics. Dirk Brouwer's death in 1966 resulted in the celestial mechanics faculty at Yale spreading across the country. The space program, radar observations, and faster computers propelled advances in celestial mechanics. Teams at the Jet Propulsion Laboratory and Massachusetts Institute of Technology developed solar system ephemerides using numerical integrations fit to optical observations and radar ranging measurements. It was time for the AAS Division on Dynamical Astronomy.

Keywords: Astrodynamics, History of astronomy, Ephemerides, Orbit determination
A Report on Stellar Companion Mass Estimates within Our Solar Neighborhood. We present mass estimates and companion demographics on stellar multiples within 25 pc, using a survey of stars of all spectral types done by Robo-AO and supplemented by Gaia. The survey combined direct imaging by Robo-AO, a robotic adaptive optics instrument for 2 m class telescopes, to detect tight companions (&lt;4″ separation) and with Gaia astrometry to detect wider co-moving companions. We estimated the masses for 267 companions using empirical relations and, for a subset of 97, dynamical mass estimates. We utilized previous mass–magnitude models using contrasts measured from Gaia and Robo-AO to estimate the mass and also used the orvara python package, a Markov Chain Monte Carlo orbit fitter using the companion astrometry and Hipparcos-Gaia proper motion accelerations, to estimate dynamical masses. We compare agreements and discrepancies in mass estimates from these two methods.

Keywords: Binary stars, Close binary stars, Center of mass, Adaptive optics, Direct imaging, Companion stars, Stellar masses, Keplerian orbit
Recent Outbursts of the High-mass X-Ray Binary CI Camelopardalis. CI Camelopardalis (CI Cam) is a High Mass X-Ray Binary (HMXB) that was discovered by the All Sky Monitor on board the Rossi X-Ray Timing Explorer when it underwent an outburst in 1998. CI Cam, also known as XTE J0421+560, peaked first in X-rays followed by optical and radio wavelengths (2.25, 8.3, 15 GHz). Several soft X-ray flares were observed after the initial flare. The optical flux was observed to quickly return to quiescent levels, while the radio flare was of much longer duration. The outburst was also detected by the X-ray satellite BeppoSax and the Burst and Transient Source Experiment on board the Compton Gamma Ray Observatory. The optical counterpart, CI Cam, is a B0-2 blue supergiant Be star and, assuming a compact object as an accretion companion (black hole, neutron star, white dwarf), the system can be designated an HMXB. Additionally, there is a pulsating third companion with periods of 0.41521 and 0.26647 days. While the initial outburst occurred in 1998, there is photometric evidence that there have been several later outbursts of similar magnitude to the original 1998 event. This paper will discuss these later outburst events as well as the identified pulsation modes.

Keywords: High mass x-ray binary stars
SALT-RSS Multiobject Spectroscopic Data Reduction to Reveal Physical Properties of [O II]-emitting Galaxies from HETDEX and ODIN. Line flux ratios from [O II] doublets can probe electron densities in the interstellar medium of galaxies. We employ the Southern African Large Telescope's (SALT) Robert Stobie Spectrograph (RSS), which provides sufficient resolution (R ∼ 3000) to split the [O II] doublets, to target galaxies from Hobby-Eberly Telescope Dark Energy Experiment and One-hundred-deg2 DECam Imaging in Narrowbands with emission line fluxes of at least 2 × 10‑16 erg cm‑2 s‑1. Reduction is carried out using RSSMOSPipeline to reduce SALT-RSS data through wavelength calibration. Despite SALT-RSS being known for its difficulty to flux calibrate, we present spectra that have been flux calibrated using alignment stars with Sloan Digital Sky Survey spectra as standards. We combine multiple spectroscopic settings to obtain full 2D spectra across a wavelength range of 3500–9500 Å. A 1D spectrum can then be extracted to calculate flux ratios and line widths, revealing important physical properties of these bright [O II]-emitters.

Keywords: Galaxy spectroscopy, Emission line galaxies, Astronomy data reduction, Spectroscopy
SpyderZ: An Efficient Support Vector Machine Library for Photometric Redshift Estimation and Redshift Probability Information. We present SpyderZ, a Python-based library for photometric redshift estimation using support vector machines (implemented with scikit-learn). Our approach discretizes redshift values into uniformly-sized bins and uses one-vs-one support vector classifiers with voting strategies to produce effective probability density functions (ePDFs) over redshift for each galaxy. These ePDFs, which are not constrained to be Gaussian or any other shape, allow for our model's predictions to be used quantitatively with uncertainty analysis methods, and have been shown to enable reliable catastrophic outlier detection. Adapted from the previous IDL package SpiderZ, SpyderZ offers training and evaluation speed optimizations on the order of 102, along with support for parallelization across CPU cores. Our library also offers in-built data sanity checks, result visualizations, metric calculations, cross validation, batch evaluations, and parallelized hyperparameter search (grid search and random search).

Keywords: Support vector machine, Redshift surveys, Photometry
Two Shell-burning White Dwarfs in Symbiotics of the Small Magellanic Cloud. SMC3 and Lin358 are super-soft X-ray sources (SSS) in symbiotics of the Small Magellanic Cloud. They have been observed as SSS for over 30 yr. We present new observations done in 2014, 2021 and in 2023 with XMM-Newton, NICER, and Chandra. Lin358 is modeled with an effective temperature around 200,000 K, and a maximum flux value around 8.25 × 10‑13 erg cm‑2 s‑1 in 2021. An observation close to periastron revealed hardening of the source. SMC3 is known to undergo an X-ray obscuration approximately every 4.5 yr; we measured the peak X-ray flux of 4.12 × 10‑13 in 2014 with the Chandra Low Energy Transmission Grating. Models indicate an effective temperature of about 500,000 K, consistent with previous findings, and increasing luminosity excursion between maxima and minima. We suggest that with such high effective temperature, indicative of steady shell burning, the possibility these systems are on the path to type Ia supernova is worth considering.

Keywords: Symbiotic binary stars, X-ray binary stars
Orbital and Precession Periods in Repeating FRB 20121102A. Li et al. reported a 4.605 days period in the repeating FRB 20121102A in addition to its previously reported 157 days modulation of activity. This note suggests that the shorter period is the orbital period of a mass-transferring star orbiting a black hole, possibly of intermediate mass, and that the 157 days period is the precession period of an accretion disk around the black hole. The mass-losing star must be evolved.

Keywords: Radio transient sources
Discovery of an [O III] Emission Shell around the X-Ray Binary CI Cam. We report the serendipitous discovery of a   $8^{\prime} \times 12^{\prime} $   emission shell brightest in [O III] centered on the X-ray binary B[e] star, CI Cameleopardalis (CI Cam). This shell, detected during a survey of optical emission associated with the Galactic supernova remnant G150.3+4.5, is seen outside but immediately adjacent to the remnant's optical filaments along its northwestern edge. Assuming this shell is related to CI Cam's strong winds and transient outbursts, the adoption of CI Cam's Gaia DR3 statistically corrected distance of 4.1  ${}_{-0.2}^{+0.3}$   kpc yields shell dimensions ≃9.5 pc × 14.3 pc. While the distance to the G150.3+4.5 remnant is uncertain, the appearance of CI Cam's emission shell so close to the SNR's optical filaments appears likely to be a chance coincidence.

Keywords: Emission nebulae, High mass x-ray binary stars, Binary stars
Constrained Wave-telescope Technique. We revisit the mathematics behind the application of the physically informed constraint matrix used in the wave-telescope technique. The constraint matrix, used to enforce the divergence-free nature of the magnetic field when processing in situ multi-spacecraft data, is found in a few different forms in the literature. We give brief analytical and computational evidence to support a particular combination of constraint matrix and spectral energy density equation for the wave-telescope technique.

Keywords: Space plasmas, Plasma physics, Analytical mathematics, Computational methods, Magnetic fields