Sazuna/UAT_keywords huggingface dataset:
Around the Spindle Galaxy: The Dark Halo Mass of NGC 3115. We report observations of five dwarf galaxies in the vicinity of the luminous S0 galaxy NGC 3115 performed with the Advanced Camera for Surveys on the Hubble Space Telescope. Their distances determined via the Tip of the Red Giant Branch are: 10.05 Mpc (UGCA 193), 9.95 Mpc (KKSG 17), 10.13 Mpc (2MASX-J0957-0915), 10.42 Mpc (2dFGRS-TGN218Z179), and 11.01 Mpc (KKSG 19). With their typical distance error of about 0.75 Mpc all the five dwarfs are consistent to be true satellites of the host galaxy NGC 3115 (10.2 ± 0.2 Mpc). Using the DESI Legacy Imaging Surveys we also found five new probable dwarf satellites of NGC 3115, as well as four new probable members of the neighboring group around NGC 3521 situated 3 Mpc away from the NGC 3115 group. Based on the radial velocities and projected separations of 10 dwarf companions, we derived the total (orbital) mass of NGC 3115 to be (4.89 ± 1.48) 1012 M ⊙. The ratio of the total mass-to-K luminosity of NGC 3115 is (50 ± 15) M ⊙/L ⊙, which is typical for the early-type luminous galaxies.

Keywords: Galaxy distances, Dwarf galaxies, Distance measure, Galaxies
Analysis of Five Double-lined Spectroscopic Eclipsing Binaries Observed with TESS and LAMOST. Based on analysis of high-precision photometry from the Transiting Exoplanet Survey Satellite combining with spectroscopy from the medium-resolution spectra of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, we investigated five double-lined spectroscopic eclipsing binaries (TIC 0165626871, TIC 0159105847, TIC 0122446076, TIC 0349294422, and TIC 0155968973). With the help of Wilson-Devinney program, we accurately derived their absolute stellar parameters. TIC 0165626871, TIC 0159105847, and TIC 0122446076 were identified as detached binaries, while TIC 0349294422 and TIC 0155968973 were recognized as A-subtype and W-subtype W UMa-type systems, respectively. Especially, absolute parameters of four binaries except for TIC 0122446076 were obtained for the first time. TIC 0165626871 also shows light variations of out-of-eclipse phases, which are probably contributed by starspots. The light pulsations of TIC 0122446076 could originate from the primary star that is located in the classical Cepheid instability strip. Evolutionary states of all stars were also discussed.

Keywords: Eclipsing binary stars
Zeta-Payne: A Fully Automated Spectrum Analysis Algorithm for the Milky Way Mapper Program of the SDSS-V Survey. The Sloan Digital Sky Survey (SDSS) has recently initiated its fifth survey generation (SDSS-V), with a central focus on stellar spectroscopy. In particular, SDSS-V's Milky Way Mapper program will deliver multiepoch optical and near-infrared spectra for more than 5 × 106 stars across the entire sky, covering a large range in stellar mass, surface temperature, evolutionary stage, and age. About 10% of those spectra will be of hot stars of OBAF spectral types, for whose analysis no established survey pipelines exist. Here we present the spectral analysis algorithm, ZETA-PAYNE, developed specifically to obtain stellar labels from SDSS-V spectra of stars with these spectral types and drawing on machine-learning tools. We provide details of the algorithm training, its test on artificial spectra, and its validation on two control samples of real stars. Analysis with ZETA-PAYNE leads to only modest internal uncertainties in the near-IR with APOGEE (optical with BOSS): 3%–10% (1%–2%) for T eff, 5%–30% (5%–25%) for  vsini , 1.7–6.3 km s‑1 (0.7–2.2 km s‑1) for radial velocity, &lt;0.1 dex (&lt;0.05 dex) for  logg , and 0.4–0.5 dex (0.1 dex) for [M/H] of the star, respectively. We find a good agreement between atmospheric parameters of OBAF-type stars when inferred from their high- and low-resolution optical spectra. For most stellar labels, the APOGEE spectra are (far) less informative than the BOSS spectra of these stars, while  logg ,  vsini , and [M/H] are in most cases too uncertain for meaningful astrophysical interpretation. This makes BOSS low-resolution optical spectra better for stellar labels of OBAF-type stars, unless the latter are subject to high levels of extinction.

Keywords: Massive stars, Stellar properties, Spectroscopy
Shallow Transits-Deep Learning. II. Identify Individual Exoplanetary Transits in Red Noise using Deep Learning. In a previous paper, we introduced a deep learning neural network that should be able to detect the existence of very shallow periodic planetary transits in the presence of red noise. The network in that feasibility study would not provide any further details about the detected transits. The current paper completes this missing part. We present a neural network that tags samples that were obtained during transits. This is essentially similar to the task of identifying the semantic context of each pixel in an image-an important task in computer vision, called "semantic segmentation," which is often performed by deep neural networks. The neural network we present makes use of novel deep learning concepts such as U-Nets, Generative Adversarial Networks, and adversarial loss. The resulting segmentation should allow further studies of the light curves that are tagged as containing transits. This approach toward the detection and study of very shallow transits is bound to play a significant role in future space-based transit surveys such as PLATO, which are specifically aimed to detect those extremely difficult cases of long-period shallow transits. Our segmentation network also adds to the growing toolbox of deep learning approaches that are being increasingly used in the study of exoplanets; but, so far mainly for vetting transits, rather than their initial detection.

Keywords: Exoplanet detection methods, Transit photometry, Neural networks
A Pluto-Charon Sonata IV. Improved Constraints on the Dynamical Behavior and Masses of the Small Satellites. We discuss a new set of ~500 numerical n-body calculations designed to constrain the masses and bulk densities of Styx, Nix, Kerberos, and Hydra. Comparisons of different techniques for deriving the semimajor axis and eccentricity of the four satellites favor methods relying on the theory of Lee &amp; Peale, where satellite orbits are derived in the context of the restricted three-body problem (Pluto, Charon, and one massless satellite). In each simulation, we adopt the nominal satellite masses derived in Kenyon &amp; Bromley, multiply the mass of at least one satellite by a numerical factor f ≥ 1, and establish whether the system ejects at least one satellite on a timescale ≤4.5 Gyr. When the total system mass is large (f ≫ 1), ejections of Kerberos are more common. Systems with lower satellite masses (f ≈ 1) usually eject Styx. In these calculations, Styx often "signals" an ejection by moving to higher orbital inclination long before ejection; Kerberos rarely signals in a useful way. The n-body results suggest that Styx and Kerberos are more likely to have bulk densities comparable with water ice, ρ SK ≲ 2 g cm-3, than with rock. A strong upper limit on the total system mass, M SNKH ≲ 9.5 × 1019 g, also places robust constraints on the average bulk density of the four satellites, ρ SNKH ≲ 1.4 g cm-3. These limits support models where the satellites grow out of icy material ejected during a major impact on Pluto or Charon.

Keywords: Natural satellite formation, Plutonian satellites, Dynamical evolution, Pluto
Zwicky Transient Facility and Globular Clusters: The RR Lyrae gri-band Period-Luminosity-Metallicity and Period-Wesenheit-Metallicity Relations. Based on time-series observations collected from the Zwicky Transient Facility (ZTF), we derived period-luminosity-metallicity (PLZ) and period-Wesenheit-metallicity (PWZ) relations for RR Lyrae located in globular clusters. We have applied various selection criteria to exclude RR Lyrae with problematic or spurious light curves. These selection criteria utilized information on the number of data points per light curve, amplitudes, colors, and residuals on the period-luminosity and/or period-Wesenheit relations. Due to blending, a number of RR Lyrae in globular clusters were found to be anomalously bright and have small amplitudes of their ZTF light curves. We used our final sample of ~750 RR Lyrae in 46 globular clusters covering a wide metallicity range (-2.36 dex &lt; [Fe/H] &lt; -0.54 dex) to derive PLZ and PWZ relations in the gri bands. In addition, we have also derived the period-color-metallicity and, for the first time, the period-Q-index-metallicity relations, where the Q-index is extinction-free by construction. We have compared our various relations to empirical and theoretical relations available in the literature and found a good agreement with most studies. Finally, we applied our derived PLZ relation to a dwarf galaxy, Crater II, and found that its true distance modulus should be larger than the most recent determination.

Keywords: Globular star clusters, Sky surveys, Wide-field telescopes, Distance indicators, RR Lyrae variable stars
Milliarcsecond Astrometry for the Galilean Moons Using Stellar Occultations. A stellar occultation occurs when a Solar System object passes in front of a star for an observer. This technique allows the sizes and shapes of the occulting body to be determined with kilometer precision. In addition, this technique constrains the occulting body's positions, albedos, densities, and so on. In the context of the Galilean moons, these events can provide their best ground-based astrometry, with uncertainties in the order of 1 mas (~3 km at Jupiter's distance during opposition). We organized campaigns and successfully observed a stellar occultation by Io (JI) in 2021, one by Ganymede (JIII) in 2020, and one by Europa (JII) in 2019, with stations in North and South America. We also re-analyzed two previously published events: one by Europa in 2016 and another by Ganymede in 2017. We then fit the known 3D shape of the occulting satellite and determine its center of figure. This resulted in astrometric positions with uncertainties in the milliarcsecond level. The positions obtained from these stellar occultations can be used together with dynamical models to ensure highly accurate orbits of the Galilean moons. These orbits can help when planning future space probes aiming at the Jovian system, such as JUICE by ESA and Europa Clipper by NASA. They also allow more efficient planning of flyby maneuvers.

Keywords: Galilean satellites, Occultation, Astrometry
Orbits of the Irregular Satellites of Uranus and Neptune. We report on an ephemerides update for the irregular satellites of Uranus and Neptune, including Nereid. Our data set contains ground-based and Voyager 2 position measurements of the satellites. Some of the new observations were reduced with respect to the GAIA star catalog and represent high-quality, modern astrometry. The orbital fits are based on the numerically integrated equations of motion. We summarized results in terms of state vectors, orbital uncertainties, and mean elements. A large number of the irregulars have not been followed up in over a decade, and our study shows that their orbits still contain significant uncertainties.

Keywords: Irregular satellites, Neptunian satellites, Orbit determination, Uranian satellites
Substellar Hyades Candidates from the UKIRT Hemisphere Survey. We have used data from the UKIRT Hemisphere Survey to search for substellar members of the Hyades cluster. Our search recovered several known substellar Hyades members, and two known brown dwarfs that we suggest may be members based on a new kinematic analysis. We uncovered thirteen new substellar Hyades candidates, and obtained near-infrared follow-up spectroscopy of each with IRTF/SpeX. Six candidates with spectral types between M7 and L0 are ruled out as potential members based on their photometric distances (≳100 pc). The remaining seven candidates, with spectral types between L5 and T4, are all potential Hyades members, with five showing strong membership probabilities based on BANYAN Σ and a convergent point analysis. Distances and radial velocities are still needed to confirm Hyades membership. If confirmed, these would be some of the lowest mass free-floating members of the Hyades yet known, with masses as low as ~30 M Jup. An analysis of all known substellar Hyades candidates shows evidence that the full extent of the Hyades has yet to be probed for low-mass members, and more would likely be recovered with deeper photometric and astrometric investigations.

Keywords: Open star clusters, Low mass stars
Scaling K2. V. Statistical Validation of 60 New Exoplanets From K2 Campaigns 2-18. The NASA K2 mission, salvaged from the hardware failures of the Kepler telescope, has continued Kepler's planet-hunting success. It has revealed nearly 500 transiting planets around the ecliptic plane, many of which are the subject of further study, and over 1000 additional candidates. Here we present the results of an ongoing project to follow-up and statistically validate new K2 planets, in particular to identify promising new targets for further characterization. By analyzing the reconnaissance spectra, high-resolution imaging, centroid variations, and statistical likelihood of the signals of 91 candidates, we validate 60 new planets in 46 systems. These include a number of planets amenable to transmission spectroscopy (K2-384 f, K2-387 b, K2-390 b, K2-403 b, and K2-398 c), emission spectroscopy (K2-371 b, K2-370 b, and K2-399 b), and both (K2-405 b and K2-406 b); several systems with planets in or close to mean motion resonances (K2-381 and K2-398) including a compact, TRAPPIST-1-like system of five small planets orbiting a mid-M dwarf (K2-384); an ultra-short-period sub-Saturn in the hot Saturn desert (K2-399 b); and a super-Earth orbiting a moderately bright (V = 11.93), metal-poor ([Fe/H] = -0.579 ± 0.080) host star (K2-408 b). In total we validate planets around four F stars, 26 G stars, 13 K stars, and three M dwarfs. In addition, we provide a list of 37 vetted planet candidates that should be prioritized for future follow-up observation in order to be confirmed or validated.

Keywords: Exoplanet catalogs, Exoplanet systems
HD 183986: A High-contrast SB2 System with a Pulsating Component. There is a small group of peculiar early-type stars on the main sequence that show different rotation velocities from different spectral lines. This inconsistency might be due to the binary nature of these objects. We aim to verify this hypothesis by a more detailed spectroscopic and photometric investigation of one such object: HD 183986. We obtained 151 high- and medium-resolution spectra that covered an anticipated long orbital period. There is clear evidence of the orbital motion of the primary component. We uncovered a very faint and broad spectrum of the secondary component. The corresponding SB2 orbital parameters, and the component spectra, were obtained by Fourier disentangling using the KOREL code. The component spectra were further modeled by iSpec code to arrive at the atmospheric quantities and the projected rotational velocities. We have proven that this object is a binary star with a period P = 1268.2(11) days, eccentricity e = 0.5728(20), and mass ratio q = 0.655. The primary component is a slowly rotating star ( $v\sin i=27$ km s-1) while the cooler and less massive secondary rotates much faster ( $v\sin i\,\sim $ 120 km s-1). Photometric observations obtained by the Transiting Exoplanet Survey Satellite (TESS) satellite were also investigated to shed more light on this object. A multiperiod photometric variability was detected in the TESS data ranging from hours (the δ Sct-type variability) to a few days (spots/rotational variability). The physical parameters of the components and the origin of the photometric variability are discussed in more detail.

Keywords: Radial velocity, Binary stars, Pulsating variable stars
Hitting a New Low: The Unique 28 hr Cessation of Accretion in the TESS Light Curve of YY Dra (DO Dra). We present the Transiting Exoplanet Surveying Satellite light curve of the intermediate polar YY Draconis (YY Dra, also known as DO Dra). The power spectrum indicates that while there is stream-fed accretion for most of the observational period, there is a day-long, flat-bottomed low state at the beginning of 2020 during which the only periodic signal is ellipsoidal variation and there is no appreciable flickering. We interpret this low state to be a complete cessation of accretion, a phenomenon that has been observed only once before in an intermediate polar. Simultaneous ground-based observations of this faint state establish that when accretion is negligible, YY Dra fades to g = 17.37 ± 0.12, which we infer to be the magnitude of the combined photospheric contributions of the white dwarf and its red dwarf companion. Using survey photometry, we identify additional low states in 2018-2019 during which YY Dra repeatedly fades to-but never below-this threshold. This implies relatively frequent cessations in accretion. Spectroscopic observations during future episodes of negligible accretion can be used to directly measure the field strength of the white dwarf by Zeeman splitting. Separately, we search newly available catalogs of variable stars in an attempt to resolve the long-standing dispute over the proper identifier of this system.

Keywords: Accretion, White dwarf stars, Stellar magnetic fields, DQ Herculis stars, Cataclysmic variable stars, DQ stars
An Aligned Orbit for the Young Planet V1298 Tau b. The alignment of planetary orbits with respect to the stellar rotation preserves information on their dynamical histories. Measuring this angle for young planets helps illuminate the mechanisms that create misaligned orbits for older planets, as different processes could operate over timescales ranging from a few megayears to a gigayear. We present spectroscopic transit observations of the young exoplanet V1298 Tau b; we update the age of V1298 Tau to be 28 ± 4 Myr based on Gaia EDR3 measurements. We observed a partial transit with Keck/HIRES and LBT/PEPSI, and detected the radial velocity anomaly due to the Rossiter-McLaughlin effect. V1298 Tau b has a prograde, well-aligned orbit, with $\lambda ={4}_{-10}^{+7}$ deg. By combining the spectroscopically measured $v\sin {i}_{\star }$ and the photometrically measured rotation period of the host star we also find that the orbit is aligned in 3D, $\psi ={8}_{-7}^{+4}$ deg. Finally, we combine our obliquity constraints with a previous measurement for the interior planet V1298 Tau c to constrain the mutual inclination between the two planets to be i mut = 0° ± 19°. This measurements adds to the growing number of well-aligned planets at young ages, hinting that misalignments may be generated over timescales of longer than tens of megayears. The number of measurements, however, is still small, and this population may not be representative of the older planets that have been observed to date. We also present the derivation of the relationship between i mut, λ, and i for the two planets.

Keywords: Exoplanet dynamics, Starspots, High resolution spectroscopy, Exoplanets, Pre-main sequence
Dayside Fe I Emission, Day-Night Brightness Contrast and Phase Offset of the Exoplanet WASP-33b. We report on Fe I in the dayside atmosphere of the ultra-hot-Jupiter WASP-33b, providing evidence for a thermal inversion in the presence of an atomic species. We also introduce a new way to constrain the planet's brightness variation throughout its orbit, including its day-night contrast and peak phase offset, using high-resolution Doppler spectroscopy alone. We do so by analyzing high-resolution optical spectra of six arcs of the planet's phase curve, using Echelle SpectroPolarimetric Device for the Observation of Stars (ESPaDOnS) on the Canada-France-Hawaii telescope and High Dispersion Spectrograph on the Subaru telescope. By employing a likelihood mapping technique, we explore the marginalized distributions of parameterized atmospheric models, and detect Fe I emission at high significance (&gt;10.4σ) in our combined data sets, located at K p = 222.1 ± 0.4 km s-1 and v sys = -6.5 ± 0.3 km s-1. Our values agree with previous reports. By accounting for WASP-33b's brightness variation, we find evidence that its nightside flux is &lt;10% of the dayside flux and the emission peak is shifted westward of the substellar point, assuming the spectrum is dominated by Fe I. Our ESPaDOnS data, which cover phases before and after the secondary eclipse more evenly, weakly constrain the phase offset to +22 ± 12 degrees. We caution that the derived volume-mixing ratio depends on our choice of temperature-pressure profile, but note it does not significantly influence our constraints on day-night contrast or phase offset. Finally, we use simulations to illustrate how observations with increased phase coverage and higher signal-to-noise ratios can improve these constraints, showcasing the expanding capabilities of high-resolution Doppler spectroscopy.

Keywords: High resolution spectroscopy, Exoplanet atmospheric composition , Hot Jupiters, Exoplanets, Astronomy data analysis, Extrasolar gaseous giant planets, Exoplanet atmospheres
Magnetic Activity on Four Short-period Contact Binaries: V0576 Peg, KW Psc, V0873 Per, and FY Boo. We presented new photometry for four short-period late-type binaries, observed by three small telescopes in China from 2020 September to 2021 December. Seven sets of light curves (including the TESS data for FY Boo) were analyzed by using the W-D method. Three binaries (V0576 Peg, V0873 Per, and FY Boo) are W-type binaries with q ≃ 2.5, while KW Psc is an A-type binary with q ≃ 0.43. Max.I-Max.II is up to 10% of variable light amplitude for the asymmetric light curves, which are modeled by a dark spot on the surface of the more massive component. Photometric results imply the existence of movement and evolution of the cool spot. From the temperature-luminosity and mass-luminosity diagrams, the more massive components are a bit evolved main-sequence stars, while the less massive ones are oversized and overluminous owing to energy exchange. Orbital period analyses indicate that the cyclic oscillations occur in the (O - C) curves. Their modulated periods approach 11 yr, which may preferably result from the magnetic activity cycle for four late-type contact binaries. With angular momentum loss through magnetic braking, these short-period contact binaries may evolve into deep-contact configurations.

Keywords: Eclipsing binary stars