Sazuna/UAT_keywords huggingface dataset:
Ellipse-fitting in Mock Images of TNG50 Barred Galaxies. Recent studies have utilized the TNG50 simulation to explore barred galaxy morphology. The ellipse-fitting method is commonly used to assess properties of the isophotes in the central region of the disk. This work adapts the ellipse-fitting method to simulated images from TNG50, dealing with the issue of excessively pronounced ellipticities in central regions, whether in mass distribution maps or simulated radiative transfer images. To solve this problem, we introduce synthetic realism in the form of convolution with point spread functions, correcting the misbehavior in central ellipticities. These improvements simplify the application of ellipse-fitting to barred galaxies in the TNG50 simulation, enabling more accurate analysis of properties such as bar length and ellipticity, which would otherwise be more difficult to measure accurately. Thus, we conclude that when measuring shapes of simulated barred galaxies, one should apply realistic smoothing, otherwise the inner ellipticities will not be comparable to observations.

Keywords: Barred spiral galaxies, Galaxy bars
Dust Grain Properties in Extragalactic Environment Through Supernovae Dust Polarization Observations. Dust polarization observations of starlight at multi-wavelengths helps us to find maximum polarization, P max and the corresponding wavelength,  . This   is approximately proportional to average grain size, thereby helping to reveal grain sizes in the intervening medium. We study the average grain sizes in different host galaxies of 4 Type Ia and 10 Type II supernovae through spectropolarimetric observations at multi-wavelengths and compare with the average grain sizes in the diffused interstellar medium of our galaxy. We use archival P max,   and width of peak of polarization curve (K) values from the literature. We plot P max versus   in color scale that represents K and find that grain sizes of some of the galaxies are smaller, some nearly comparable and some larger than typical grain size (≈5500 Å) of our galaxy. This gives us an insight into the different grain properties especially their sizes in external galaxies compared to our galaxy.

Keywords: Interstellar dust, Starlight polarization, Spectropolarimetry
Well-balanced Hydrodynamics for the Piecewise Parabolic Method with Characteristic Tracing. Well-balanced reconstruction techniques have been developed for stellar hydrodynamics to address the challenges of maintaining hydrostatic equilibrium during evolution. I show how to adapt a simple well-balanced method to the piecewise parabolic method for hydrodynamics. A python implementation of the method is provided.

Keywords: Hydrodynamical simulations, Computational methods, Open source software, Hydrodynamics
Comment on "Excluding Primordial Black Holes as Dark Matter Based on Solar System Ephemeris". It was recently claimed (https://arxiv.org/pdf/2408.10799) that solar system ephemeris data can exclude primordial black hole (PBH) dark matter in the mass range 1018–1022 g. I show that this conclusion is based on an implausible, implicit assumption; namely the uncertainty on the solar system mass within 50 au is as small as the uncertainty on the mass of the Sun. Correcting for this error, I find that ephemeris data can only constrain PBH's with mass below 1016 g, which is already excluded by constraints on their evaporation via Hawking radiation. Correcting a further error concerning the time-averaged rate of such fluctuations nullifies even this weaker constraint.

Keywords: Primordial black holes
Determination of the Abundance of Mercury from the Hg II Line at 5677.10 Å in Late B-type Stars. VI. HD 173524 (46 Dra). The weak line of Hg II located at 5677.10 Å is used to measure the mercury abundance in the most massive component of the SB2 HgMn star HD 173524 (46 Dra). This line is detected at 3σ above the noise in the adjacent continuum. The synthesis of this line, confirms a large overabundance of mercury, about +5.00 dex, which is less than the excess derived from the 3983.93 Å line in earlier studies. Spectrum synthesis yields estimates of the abundance deficiencies/excesses for sixteen other elements. Helium, carbon, oxygen, magnesium, silicon, chromium and iron are depleted. Phosphorus, titanium, manganese, gallium, strontium, yttrium, zirconium and barium are overabundant. Platinum is very overabundant. For several elements, these new abundances differ from earlier measurements.

Keywords: Mercury-manganese stars, Chemically peculiar stars
The Dispersion Relation of Massive Photons in Plasma: A Comment on "Bounding the Photon Mass with Ultrawide Bandwidth Pulsar Timing Data and Dedispersed Pulses of Fast Radio Bursts". The dispersion measures of fast radio bursts have been identified as a powerful tool for testing the zero-mass hypothesis of the photon. The classical approach treats the massive photon-induced and plasma-induced time delays as two separate phenomena. Recently, Y.-B. Wang et al. suggested that the joint influence of the nonzero photon mass and plasma effects should be considered, and proposed a revised time delay for massive photons propagating in a plasma medium, denoted as  , which departures from the classical dispersion relation (∝ν ‑2). Here we discuss the derivation presented by Y.-B. Wang et al. and show that the classical dispersion relation remains valid based on Proca equations.

Keywords: Intergalactic medium, Particle astrophysics, Radio transient sources
Revisiting WASP-19b's Orbital Evolution: New TESS Data and Apsidal Precession Analysis. Due to the ongoing debate of whether WASP19b is experiencing orbital decay or apsidal precession, I reexamine the orbital evolution of the hot Jupiter WASP-19b using new TESS data from sectors 09, 36, 62, and 63. My comprehensive analysis of transit and occultation timing variations compares models of constant period, orbital decay, and apsidal precession. Results show no significant preference between orbital decay and apsidal precession models. I find a period change rate of ‑1.40 ± 0.54 ms yr‑1, slower than some previous studies but consistent with others. My apsidal precession analysis yields an eccentricity of 0.00178 and a precession rate of 0.036 deg day‑1, differing from recent literature. These findings underscore the complexity of WASP-19b's orbital dynamics and the need for continued long-term monitoring.

Keywords: Exoplanets, Transit timing variation method, Hot Jupiters
A Two-month Mini-moon: 2024 PT<SUB>5</SUB> Captured by Earth from September to November. Near-Earth objects (NEOs) that follow horseshoe paths, and approach our planet at close range and low relative velocity, may undergo mini-moon events in which their geocentric energy becomes negative for hours, days or months, but without completing one revolution around Earth while bound. An example of NEO experiencing such a temporarily captured flyby is 2022 NX1, which was a short-lived mini-moon in 1981 and 2022. Here, we show that the recently discovered small body 2024 PT5 follows a horseshoe path and it will become a mini-moon in 2024, from September 29 until November 25.

Keywords: Solar system, Asteroids
Cometary Activity from Minor Planet 2015 VP<SUB>51</SUB> Discovered with Citizen Science. We report the discovery of cometary activity emanating from minor planet 2015 VP51 outbound from its recent perihelion passage. The activity, in the form of a diffuse tail, was first identified by volunteers of our Citizen Science program Active Asteroids, a NASA Partner program hosted on the Zooniverse platform. This discovery was aided by the recently implemented TailNet artificial intelligence assistant which filters out images with a low likelihood of showing cometary activity. The tail is present in nine images of 2015 VP51 from the Dark Energy Camera and OmegaCAM between UT 2015 August 2 and UT 2015 October 18. We classify 2015 VP51 as a Jupiter-family comet based on its Tisserand parameter with respect to Jupiter T J = 2.931.

Keywords: Comet tails, Short period comets, Comae
New Sample of Ultracool Dwarf Benchmarks with Detailed Chemical Characterization. Ultracool dwarfs (UCDs) are considered prime targets for galactic archeology due to their abundance, long lifespans, and the sensitivity of their spectra to chemical composition. To calibrate larger surveys, a sample of benchmark UCDs with robust abundances is necessary. We present [Fe/H], [α/Fe] and abundances of 13 elements, inferred from high-resolution spectra of 13 FGK primaries hosting a UCD companion. For a subset of our sample with APOGEE observations, individual abundances agree within 0.06 dex on average.

Keywords: Galactic archaeology, Brown dwarfs, Chemical abundances, Spectroscopy
New Transit Timing Observations of WASP-12b from TESS Sectors 71 and 72. I present new transit and occultation timing measurements for the hot Jupiter WASP-12b using data from TESS Sectors 71 and 72, observed in 2023. Using full-phase curve fitting for the first time, I precisely locate both transits and occultations. I report 34 new transit times and sector-specific occultation times, updating the orbital decay rate to ‑26.310 ± 0.901 ms yr‑1. My analysis strongly favors the orbital decay model over constant period and apsidal precession models.

Keywords: Hot Jupiters, Transit timing variation method, Exoplanets
A Strong Lensing Model of RCS1 J0224‑0002.5. We present the details of a strong lensing model of RCS1 J0224‑0002.5, a strong lensing cluster at z = 0.773, based on data from Hubble Space Telescope/WFC3, Advanced Camera for Surveys, and WFC2. Of particular interest in this field is a z = 4.8786 Lyα emitter (LAE), 15″ from the brightest cluster galaxy (BCG) that stretches northwest to west of the BCG in three different images, with a fourth counter-image ∼4″ southeast of the BCG. Using methods consistent with those used in studying five other LAEs in A. Navarre et al., we find that the cluster is best modeled by two cluster-scale dark matter halos aligned nearly perpendicular to each other at the center of the cluster. A z = 2.396 source is also lensed with six images, providing several constraints that were instrumental in producing this model.

Keywords: Galaxy clusters, Strong gravitational lensing
New Pulsating Variable Stars and Eclipsing Binaries Around BL Cam. Based on publicly available Transiting Exoplanet Survey Satellite data, I conducted a regional survey around the SX Phe star BL Cam, spanning a radius of two degrees. This research identified 285 new variables including: 96 δ Scuti stars, 56 γ Doradus stars, 17 eclipsing binary systems with three exhibiting pulsating or rotating components, 3 rotating ellipsoidal variable stars, among others. No new SX Phe stars were identified. *Dedicated to my wife Jingyun Zhang.

Keywords: Eclipsing binary stars, Gamma Doradus variable stars, Delta Scuti variable stars, Pulsating variable stars
Landed Planetary Sensor Model Support with the Community Sensor Model. This note describes recent work to develop landed planetary sensor model support conforming to the widely adopted Community Sensor Model (CSM) standard. We describe the CSM specification and its use in the planetary sciences, introduce the test sensors carried aboard the Mars Science Laboratory Curiosity Rover, and describe the engineering research requirements fulfilled. Ultimately, we demonstrate use of a CSM framing sensor model for the NavCam and MastCam instruments including stereo terrain extraction and map projection using the NASA Ames Stereo Pipeline over a multi-day traverse and multi-image correspondence identification needed as an input to stereophotogrammetric block bundle adjustment using the USGS-maintained Integrated Software for Imagers and Spectrometers library.

Keywords: Photogrammetry, Rovers, Planetary science
The Far-ultraviolet Spectrum of FU Ori South. The eruptive young stellar object FU Ori is the eponym of its variable class. FU Ori stars are known to undergo outbursts with amplitudes of &gt;4 mag in the V band and durations of several decades. Interaction with a binary companion is one proposed outburst trigger, so understanding both components of the FU Ori system is crucial. A recent Hubble Space Telescope/Space Telescope Imaging Spectrograph observation of the FU Ori system clearly resolves its North and South components. We report here on the spectrum of FU Ori South. We detect near-ultraviolet continuum emission but no far-ultraviolet continuum, although several bright emission lines consistent with those seen in T Tauri stars are present. The presence of the C II] 2325 multiplet and many H2 lines indicate active accretion. We estimate the extinction to the source and find that the UV spectrum favors A  V  &lt; 4, contrary to past estimates based on the near-infrared spectrum.

Keywords: Ultraviolet spectroscopy, Classical T Tauri stars, Stellar accretion, FU Orionis stars
Another Independent Discovery of the 1946 Eruption of the Recurrent Nova T Coronae Borealis. One of the earliest independent discoveries of the 1946 eruption of the recurrent nova T Coronae Borealis was by British amateur astronomer, Michael Woodman, on 1946 February 9 at ∼01:45 UT when the nova was magnitude ∼2.0. Though credited as an independent discovery at the time, only scant details appeared in contemporary reports. The circumstances of Woodman's discovery are told from Woodman's contemporaneous notes and his own recollections.

Keywords: Novae
Predicting the Number of Radio Sources seen by both VLASS and LSST. Radio surveys typically sample extragalactic sources in higher redshift regimes than is typical for optical surveys, resulting in many radio sources not having a detected optical counterpart. Over the next decade the Legacy Survey of Space and Time (LSST) will be performing the deepest (i &lt; 26.4 mag) wide-area optical survey to date increasing the fraction of radio sources for which we have optical data. In this Research Note we use the Hyper Suprime-Cam survey to analyze how the fraction of radio sources in the Very Large Array Sky Survey (VLASS) with optical detections varies as a function of i-band magnitude and extrapolate to predict the number of optical counterparts we expect LSST to detect. Assuming a final VLASS point source depth of S 3 GHz ≲ 350 μJy, we expect LSST to identify optical counterparts to ∼106 radio sources in VLASS.

Keywords: Sky surveys, Optical astronomy, Optical identification, Extragalactic astronomy, Radio astronomy
Citizen Scientists Discover "Asteroid in a Cometary Orbit" 2010 MK<SUB>43</SUB> has a Comet Tail. We present the discovery of a short, diffuse tail on minor planet 2010 MK43 (alternate designation 2010 RA78)—an object previously identified as an asteroid in a cometary orbit—by volunteers of our Citizen Science program Active Asteroids. Our follow-up investigation revealed eight Dark Energy Camera images showing 2010 MK43 with a tail spanning UT 2024 February 12–UT 2024 February 18 when the object was outbound from perihelion. We now classify 2010 MK43 as a Jupiter-family comet based on its Tisserand parameter with respect to Jupiter T J = 2.888, though our dynamical simulations reveal that, due to frequent close encounters with Jupiter, 2010 MK43 was likely a quasi-Hilda within the last 10 kyr.

Keywords: Comet tails, Asteroids, Comae
A Potential Host Galaxy Association for FRB 20190605C. We present a probable host galaxy of the fast radio burst FRB 20190605C, detected by the Canadian Hydrogen Intensity Mapping Experiment. The localization was enabled by saved baseband data; the region contained one galaxy with a photometric redshift consistent with the dispersion measure of the FRB. This galaxy was identified as the most likely host with a Probabilistic Association of Transients to their Hosts probability calculation, finding a probability of association P(O∣x) = 0.913. With Prospector, we used a joint spectro-photometric fit to model stellar mass, star formation rate, metallicity, age, and a spectral energy distribution for the host candidate.

Keywords: Galaxies, Radio transient sources
LP349-25AB: Application of Magneto-convection Model to an M Dwarf Binary Where Radio and Astrometric Data have Yielded Masses with 0.7% Precision. Reliable (±(1–2)%) estimates of stellar masses have typically been obtained from eclipsing binaries. In such cases, derived values of radii and T eff are in many cases discrepant relative to standard models, especially in active stars. These discrepancies led to the development of magneto-convection theory. Recently, an independent technique has emerged for determining precise masses of radio-emitting binary components: interferometric observations at multiple points around the orbit. S. Curiel et al. have used this technique to determine the masses of both components of an M8+M9 binary (LP349-25AB) with remarkably high precision: ±0.7%. However, applying standard models suggests that the components are not co-eval, differing in age by ∼30%. But LP349-25 is such a close binary (with a separation of 1.2 au) that non-coevality seems unrealistic. Here, we report on magneto-convective modeling which resolves the apparent non-coevality while simultaneously explaining why the primary component is variable, but the secondary component is not.

Keywords: M dwarf stars, Magnetic stars, Radio astrometry
HD 34382: A Photometrically Identified Candidate Centrifugal Magnetosphere Star. We identify the chemically peculiar B8/9V star HD 34382 as a candidate member of the rare class of rapidly rotating magnetic B stars. TESS photometry shows eclipses and smooth sinusoidal variability with a period of 2.46 days. We supplement this with Keck/HIRES spectroscopy, which shows that this is a Bp star. The data suggest that the star's photometric variability results from a combination of chemical surface spots and eclipses by dense, magnetically confined plasma clouds, making this star's behavior analogous to that of stars like σ Ori E. If the star's magnetic nature is confirmed through spectropolarimetry, then HD 34382 may possess the longest rotational period known for such stars with photometrically detectable centrifugal magnetospheres. Furthermore, the star's low temperature could make HD 34382 the coolest star of its class in which such detected centrifugal magnetosphere derived photometric variability has been observed, pending such magnetic confirmation.

Keywords: Bp stars, Magnetic stars, Variable stars, Magnetic variable stars, Chemically peculiar stars
Gemini Near-infrared Photometry for a Sample of Cold Brown Dwarfs Discovered by Backyard Worlds: Planet 9. We present Gemini Observatory follow-up J-band and K-band photometry for a sample of 16 T/Y dwarf candidates discovered by the Backyard Worlds: Planet 9 citizen science project. The Gemini observations were taken with Gemini-North using the Near-Infrared Imager instrument between 2017 September and 2018 March. Obtaining near-infrared photometry of very cold brown dwarfs is important for enabling and prioritizing future spectroscopic follow-up, particularly in the context of JWST spectroscopy of T and Y dwarfs.

Keywords: Infrared astronomy, Brown dwarfs, Y dwarfs, T dwarfs
No Pulsar Timing Noise from Brownian Motion of the Sun. It was recently claimed that evidence for a stochastic gravitational wave background observed by pulsar timing arrays can be attributed instead to random perturbations of the Sun's motion by transiting asteroids. I show that that this would lead to a large dipole component accompanying a much smaller quadrupolar perturbation of pulsar timing signals, which would not be confused with a gravitational wave signal. Such an anomalous dipole would have been detected and identified as a spurious background by the PTA collaborations, if it existed.

Keywords: Gravitational wave astronomy
Christian Huygens and William Derham and 18th Century Precursors to the Habitable Zone. Both Christian Huygens and William Derham expressed ideas that are prescient to the concept of a circumstellar habitable zone: liquid water is a precondition for life, there is a region within the solar system within which liquid surface water can exist upon planets, the stars are suns around which planetary systems should be common, these extrasolar planetary systems may include habitable worlds. Although neither author explicitly developed the phraseology of an exoplanetary habitable zone based upon liquid water, such a concept would follow from their writings.

Keywords: Habitable zone, Exoplanets
Determination of the Abundance of Mercury from the Hg II Line at 5677.10 Å in Late B-type Stars. VII. HD 141556 (χ Lupi). The weak line of Hg II located at 5677.10 Å is used to measure the mercury abundance in the most massive component of the double-lined spectroscopic binary HgMn star HD 141556 (χ Lupi). This line is detected at 3σ above the noise in the adjacent continuum. The synthesis of this line confirms a large overabundance of mercury, about +5.30 dex, which is about twice the excess derived from the 3983.93 Å line in earlier studies. Spectrum synthesis yields estimates of the abundance deficiencies/excesses for fourteen other elements which agree well with previous measurements.

Keywords: Mercury-manganese stars, Chemically peculiar stars
NICER Observes the Full Z-track in GX 13+1. We present the temporal analysis of the persistent neutron star low-mass X-ray binary GX 13+1 using NICER data. Classification of this source has been ambiguous so far. We investigate the evolution of the source in its hardness–intensity diagram (HID) and power density spectra (PDS) of the 0.5–10 keV NICER archival data. For the first time, we detect the source tracing out the entire Z-track, distinctly identifying the horizontal branch (HB), normal branch (NB) and flaring branch (FB). We also detect a peaked noise component in the PDS at ∼5.4 Hz, which appears to be present when the source is either in the NB or FB. We note a positive slope of the HB in the HID which could be due to either the high intrinsic absorption of the source or the stronger contribution of the soft spectral components in the soft energy domain.

Keywords: Low-mass x-ray binary stars, Neutron stars
On the Value of High Precision Radial Velocity Observations and Astrometric Orbits for Binary Stars Hosting Exoplanets. Observations have concluded that exoplanet hosting binary stars appear to have wider mean separations than a definitive sample of "field binaries" as well as an apparent deficit of very close pairs. Many exoplanets orbit near their host stars equatorial plane, especially for close-in, small planets. Precision radial velocities of exoplanets in close binary stars are sparse but badly needed in order to provide statistical samples revealing the host stars spin axis and determinations of the masses and orbital planes of their planets. Astrometric orbits of the stars can provide precise binary orbital elements. In the quest for occurrence rates, the detection of planets is biased against transit recognition of small planets in binary systems. Together the measurements of binary host stars and their planets are required to yield robust tests of planet formation, stability, and evolution mechanisms as well as provide correct small planet occurrence rates.

Keywords: Astrometric binary stars, Binary stars, Exoplanets
Unveiled Pulsating Nature of IX Delphinus. IX Del is a variable star that was classified as uncertain E/SD at the Variable Star Index. The SSV-UAI-GRAV (Unione Astrofili Italiani, Variable Star Section) suggested a campaign to observe the star in order to understand its true nature. The Štefánik and Ďáblice observatories in Prague also collaborated in the observing campaign of the Italian section. From 2024 August to 2024 September, 10 observing sessions were obtained with terrestrial telescopes and V-band CCDs. From the analysis of the data thus obtained, combined with the Zwicky Transient Facility data, the star IX Del has been reclassified as an RRab-type variable with a pulsation period of 0.540914 day and a range of 1.36 mag g. The Blazhko effect from the result of this work is evident.

Keywords: RRab variable stars, Variable stars, Blazhko effect