Sazuna/UAT_keywords huggingface dataset:
Long-term Photometry and Orbital Period Change of the W UMa-type Binary v0599 Aur: Evidence of about 11 yr Magnetic-activity Cycle. Combining all available photometric data from various surveys and literature with our observations, we present 10 sets of light curves for the eclipsing binary V0599 Aur covering a timescale of 20 yr. During the last two decades, the O'Connell effect continuously varied and went through at least two flips between positive and negative effects. The photometric solutions from our two sets of multicolored light curves show that V0599 Aur is a W-type shallow contact binary with an active spot on the secondary. Its absolute parameters are determined by combining the Gaia distance with the photometric solutions. The period investigation reveals a secular decrease and a cyclic variation in its orbital period. The former mainly originates from the mass transfer from the more massive secondary to the less massive primary. The latter can be preferentially explained as a result of cyclic magnetic activity of the secondary, with three observational supports: (1) the existence and evolution of an active spot suggested by the long-term photometry, (2) periodic variation in both the O'Connell effect and relative luminosity, and (3) weak correlations between O'Connell effect/relative luminosity changes and cyclic period variation. Together with the cyclic period variation and its theoretical reasonability by Applegate's mechanism, we suggest that the secondary of V0599 Aur is a solar-type magnetic-activity star with an approximately 11 yr active cycle. Furthermore, by combining the secular period decrease with the Roche-lobe model, we infer that V0599 Aur is evolving from the marginal contact state controlled by thermal relaxation oscillation theory to the overcontact state.

Keywords: Starspots, CCD photometry, Close binary stars, W Ursae Majoris variable stars, Stellar activity, Eclipsing binary stars, Stellar evolution
Observations of Disequilibrium CO Chemistry in the Coldest Brown Dwarfs. Cold brown dwarfs are excellent analogs of widely separated, gas giant exoplanets, and provide insight into the potential atmospheric chemistry and physics we may encounter in objects to be discovered by future direct imaging surveys. We present a low-resolution, R ∼ 300, M-band spectroscopic sequence of seven brown dwarfs with effective temperatures between 750 and 250 K along with Jupiter. These spectra reveal disequilibrium abundances of carbon monoxide (CO) produced by atmospheric quenching. We use the eddy diffusion coefficient (Kzz) to estimate the strength of vertical mixing in each object. The Kzz values of cooler gaseous objects are close to their theoretical maximum, and warmer objects show weaker mixing, likely due to less efficient convective mixing in primarily radiative layers. The CO-derived Kzz values imply that disequilibrium phosphine (PH3) should be easily observable in all of the brown dwarfs, but none as yet show any evidence for PH3 absorption. We find that ammonia is relatively insensitive to atmospheric quenching at these effective temperatures. We are able to improve the fit to WISE 0855's M-band spectrum by including both CO and water clouds in the atmospheric model.

Keywords: Brown dwarfs, Exoplanets, Y dwarfs, Planetary atmospheres, Free floating planets, T subdwarfs, Extrasolar gaseous giant planets, Exoplanet atmospheres
KMT-2019-BLG-1339L: An M Dwarf with a Giant Planet or a Companion near the Planet/Brown Dwarf Boundary. We analyze KMT-2019-BLG-1339, a microlensing event with an obvious but incompletely resolved brief anomaly feature around the peak of the light curve. Although the origin of the anomaly is identified to be a companion to the lens with a low mass ratio q, the interpretation is subject to two different degeneracy types. The first type is the ambiguity in ρ, representing the angular source radius scaled to the angular radius of the Einstein ring, θE, and the other is the s ↔ s-1 degeneracy. The former type, "finite-source degeneracy," causes ambiguities in both s and q, while the latter induces an ambiguity only in s. Here, s denotes the separation (in units of θE) in projection between the lens components. We estimate that the lens components have masses $({M}_{1},{M}_{2})\sim ({0.27}_{-0.15}^{+0.36}\,{M}_{\odot },{11}_{-7}^{+16}\,{M}_{{\rm{J}}})$ and $\sim ({0.48}_{-0.28}^{+0.40}\,{M}_{\odot },{1.3}_{-0.7}^{+1.1}\,{M}_{{\rm{J}}})$ according to the two solutions subject to the finite-source degeneracy, indicating that the lens comprises an M dwarf and a companion with a mass around the planet/brown dwarf boundary or a Jovian-mass planet. It is possible to lift the finite-source degeneracy by conducting future observations utilizing a high-resolution instrument because the relative lens-source proper motion predicted by the solutions is widely different.

Keywords: Gravitational microlensing, Gravitational microlensing exoplanet detection
Massive Stars in Molecular Clouds Rich in High-energy Sources: The Bridge of G332.809-0.132 and CS 78 in NGC 6334. Detections of massive stars in the direction of the H II region CS 78 in NGC 6334 and of G332.809-0.132 are here presented. The region covered by the G332.809-0.132 complex coincides with the RCW 103 stellar association. In its core (40' in radius), approximately 110 OB candidate stars (Ks &lt; 10 mag and 0.4 &lt; ${A}_{{K}_{s}}$ &lt; 1.6 mag) were identified using 2MASS, DENIS, and GLIMPSE data. This number of OB stars accounts for more than 50% of the observed number of Lyman continuum photons from this region. Medium-resolution K-band spectra were obtained for seven early types, including one WN 8 star and one Ofpe/WN 9 star; the latter is located near the RCW 103 remnant and its luminosity is consistent with a distance of ≍3 kpc. The area analyzed encloses 9 of the 34 OB stars previously known in RCW 103, as well as IRAS 16115-5044, which we reclassify as a candidate luminous blue variable. The line of sight is particularly interesting, crossing three spiral arms; a molecular cloud at -50 (with RCW 103 in the Scutum-Crux arm) and another at -90 km s-1 (in the Norma arm) are detected, both rich in massive stars and supernova remnants. We also report the detection of a B supergiant as the main ionizing source of CS 78, 2MASS J17213513-3532415. Medium-resolution H- and K-band spectra display H I and He I lines, as well as Fe II lines. By assuming a distance of 1.35 kpc, we estimate a bolometric magnitude of -6.16, which is typical of supergiants. ∗ Based on observations collected at the European Southern Observatory (ESO Programmes 087.D-09609). † M.M. is currently employed by USTC. This works was designed during her ESA fellowship (2010) and partially carried out at the MPIfR.

Keywords: Early-type emission stars, Supergiant stars, Infrared sources, Stellar evolution
A Catalog of Holes and Shells in the Interstellar Medium of the LITTLE THINGS Dwarf Galaxies. We present a catalog of holes and shells in the neutral atomic hydrogen (H I) of 41 gas-rich dwarf galaxies in LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The H I Nearby Galaxy Survey). We analyzed their properties as part of an investigation into the relation between star formation and structures and kinematics in the H I of small galaxies. We confirmed 306 holes between 38 pc (our resolution limit) and 2.3 kpc, with expansion velocities up to 30 km s-1. The global star formation rates (SFRs) measured by Hα and far-UV (FUV) emission are consistent with those estimated from the energy required to create the cataloged holes in our sample. Although we found no obvious correlation between global SFRs and the H I surface and volume porosities of our sample, two of the four galaxies with the lowest porosity and the two galaxies with the highest porosity have no recent star formation as measured by Hα and FUV emission.

Keywords: Dwarf irregular galaxies, Star formation, Interstellar medium, HI shells
EXPRES. I. HD 3651 as an Ideal RV Benchmark. The next generation of exoplanet-hunting spectrographs should deliver up to an order of magnitude improvement in radial velocity (RV) precision over the standard 1 ${\rm{m}}\ {{\rm{s}}}^{-1}$ state-of-the-art spectrographs. This advance is critical for enabling the detection of Earth-mass planets around Sun-like stars. New calibration techniques such as laser frequency combs and stabilized etalons ensure that the instrumental stability is well characterized. However, additional sources of error include stellar noise, undetected short-period planets, and telluric contamination. To understand and ultimately mitigate error sources, the contributing terms in the error budget must be isolated to the greatest extent possible. Here, we introduce a new high-cadence RV program, the Extreme Precision Spectrograph (EXPRES) 100 Earths Survey, which aims to identify rocky planets around bright, nearby G and K dwarfs. We also present a benchmark case: the 62 day orbit of a Saturn-mass planet orbiting the chromospherically quiet star, HD 3651. The combination of high eccentricity (0.6) and a moderately long orbital period ensures significant dynamical clearing of any inner planets. Our Keplerian model for this planetary orbit has a residual rms of 58 cm s-1 over a ∼6 month time baseline. By eliminating significant contributors to the RV error budget, HD 3651 serves as a standard for evaluating the long-term precision of extreme precision RV programs.

Keywords: Exoplanet dynamics, Radial velocity, Exoplanet astronomy, Planet hosting stars
A Census of Star Formation in the Outer Galaxy. II. The GLIMPSE360 Field. We have conducted a study of star formation in the outer Galaxy from 65°&lt; l &lt; 265° in the region observed by the GLIMPSE360 program. This Spitzer warm mission program mapped the plane of the outer Milky Way with IRAC at 3.6 and 4.5 μm. We combine the IRAC, Wide-field Infrared Survey Explorer (WISE), and Two Micron All Sky Survey catalogs and our previous results from another outer Galaxy survey and identify a total of 47,338 young stellar objects (YSOs) across the field spanning &gt;180° in Galactic longitude. Using the DBSCAN method on the combined catalog, we identify 618 clusters or aggregations of YSOs having five or more members. We identify 10,476 class I, 29,604 class II, and 7325 anemic class II/class III YSOs. The ratio of YSOs identified as members of clusters was 25,528/47,338, or 54%. We found that 100 of the clusters identified have previously measured distances in the WISE H II survey. We used these distances in our spectral energy distribution (SED) fitting of the YSOs in these clusters, of which 96 had YSOs with &lt;3σ fits. We used the derived masses from the SED model fits to estimate the initial mass function (IMF) in the inner and outer Galaxy clusters; dividing the clusters by galactocentric distances, the slopes were Γ = 1.87 ± 0.31 above 3 M☉ for RGal &lt; 11.5 kpc and Γ = 1.15 ± 0.24 above 3 M☉ for RGal &gt; 11.5 kpc. The slope of the combined IMF was found to be Γ = 1.92 ± 0.42 above 3 M☉. These values are consistent with each other within the uncertainties and with literature values in the inner Galaxy high-mass star formation regions. The slopes are likely also consistent with a universal Salpeter IMF.

Keywords: Star forming regions, Stellar mass functions, Infrared excess, Young stellar objects, Star formation, Protoplanetary disks, Circumstellar disks, Protostars, Milky Way Galaxy
Spectroscopic Orbits of Subsystems in Multiple Stars. VII.. Spectroscopic orbits of main-sequence stars HIP 3150A, 6873B, 11537A, 22531A, 22534B, 31089B, 49336A, 104833C, and 107731A belonging to eight multiple systems are determined from high-resolution spectra taken with CHIRON. Two of those are twins with mass ratios above 0.95. HIP 11537 is a young three-tier quadruple system with inner periods of 22.3 and 1146 days and the outer period of 3 kyr. HIP 22531 (ι Pic) is the brightest star in a hierarchical system with six components. It is a spectroscopic binary with periods of 1.56 days and 2.75 yr, as well as a γ Dor variable with a period of 0.67 day, possibly in a 7:3 resonance with the inner orbit. HIP 22534, also member of this system, is a double-lined binary with a period of 208 days. For HIP 31089, both the spectro-interferometric 32 yr outer orbit and the 213 day orbit of the subsystem are determined. HIP 107731 is a triple system with an inner period of 470 days and a fast spatial motion, likely metal-poor. New orbits contribute to the statistics of hierarchical multiplicity in the solar neighborhood.

Keywords: Spectroscopic binary stars, Visual binary stars
Optical Studies of Eight AM Herculis-type Cataclysmic Variable Stars. We report detailed follow-up observations of eight cataclysmic variable stars (CVs) that are apparently AM Her stars, also called polars. For all, we either determine orbital periods for the first time or improve on existing determinations. The seven for which we have spectra show the high-amplitude radial-velocity curves and prominent He II λ4686 emission lines characteristic of strongly magnetic CVs, and their periods, which range from 81 to 219 minutes, are also typical for AM Her stars. Two objects from the Gaia-alerts index, Gaia18aot and Gaia18aya, are newly identified as CVs. Another, RX J0636.3+6554, eclipses deeply, while CSS 080228:081210+040352 shows a sharp dip that is apparently a partial eclipse. The spectrum of Gaia18aya has a cyclotron harmonic near λ5500 Å that constrains the surface field to ∼49 MG or greater.

Keywords: Close binary stars, White dwarf stars, Interacting binary stars, Eclipsing binary stars, Cataclysmic variable stars, AM Herculis stars
Using the Baryonic Tully-Fisher Relation to Measure H<SUB>o</SUB>. We explore the use of the baryonic Tully-Fisher relation (bTFR) as a new distance indicator. Advances in near-IR imaging and stellar population models, plus precise rotation curves, have reduced the scatter in the bTFR such that distance is the dominant source of uncertainty. Using 50 galaxies with accurate distances from Cepheids or the tip magnitude of the red giant branch, we calibrate the bTFR on a scale independent of Ho. We then apply this calibrated bTFR to 95 independent galaxies from the SPARC sample, using CosmicFlows-3 velocities, to deduce the local value of Ho. We find Ho = 75.1 ± 2.3 (stat) ±1.5 (sys) km s-1 Mpc-1.

Keywords: Cosmology, Hubble constant
A Gas Giant Planet in the OGLE-2006-BLG-284L Stellar Binary System. We present the analysis of microlensing event OGLE-2006-BLG-284, which has a lens system that consists of two stars and a gas giant planet with a mass ratio of qp = (1.26 ± 0.19) × 10-3 to the primary. The mass ratio of the two stars is qs = 0.289 ± 0.011, and their projected separation is ss = 2.1 ± 0.7 au, while the projected separation of the planet from the primary is sp = 2.2 ± 0.8 au. For this lens system to have stable orbits, the three-dimensional separation of either the primary and secondary stars or the planet and primary star must be much larger than the projected separations. Since we do not know which is the case, the system could include either a circumbinary or a circumstellar planet. Because there is no measurement of the microlensing parallax effect or lens system brightness, we can only make a rough Bayesian estimate of the lens system masses and brightness. We find host star and planet masses of ${M}_{L1}={0.35}_{-0.20}^{+0.30}\,{M}_{\odot }$ , ${M}_{L2}={0.10}_{-0.06}^{+0.09}\,{M}_{\odot }$ , and ${m}_{p}={144}_{-82}^{+126}\,{M}_{\oplus }$ , and the K-band magnitude of the combined brightness of the host stars is ${K}_{L}={19.7}_{-1.0}^{+0.7}$ . The separation between the lens and source system will be ∼90 mas in mid-2020, so it should be possible to detect the host system with follow-up adaptive optics or Hubble Space Telescope observations.

Keywords: Finite-source photometric effect, Gravitational microlensing exoplanet detection, Triple lens microlensing, Gravitational microlensing
The Asteroid Rotation Period Survey Using the China Near-Earth Object Survey Telescope (CNEOST). We initiated the bilateral collaboration between the Lulin Observatory and the Purple Mountain Observatory to collect asteroid lightcurves using the Chinese Near-Earth Object Survey Telescope at the Xuyi Observation Station. The primary goal of this collaboration was to discover super-fast rotators (SFRs) and study their physical properties. Two campaigns have been conducted: (a) a survey of ∼45 deg2 using 8 minute cadence during 2017 February 26-March 2, and (b) a survey of ∼60 deg2 using 10 minute cadence during 2018 March 9-12. Our samples are mainly main-belt asteroids and some Hildas and Jupiter Trojans. Out of 4522 collected lightcurves, 506 reliable rotation periods were obtained. Among the reliable rotation periods, we found 16 candidates with a possible rotation period of &lt;2.2 hr, in which (134291) 2006 DZ6 shows a very convincing folded lightcurve and the other 15 candidates only have a likely trend. Further confirmation is needed for the rotation periods of these SFR candidates. In addition, (2280) Kunikov seems to have an eclipsing feature on its lightcurve with a relatively long rotation period suggesting that it is likely a fully synchronized binary asteroid. When the preliminary spin-rate distributions were carried out for asteroids using different sizes, no obvious difference was found.

Keywords: Period determination, Asteroids
OGLE-2017-BLG-0406: Spitzer Microlens Parallax Reveals Saturn-mass Planet Orbiting M-dwarf Host in the Inner Galactic Disk. We report the discovery and analysis of the planetary microlensing event OGLE-2017-BLG-0406, which was observed both from the ground and by the Spitzer satellite in a solar orbit. At high magnification, the anomaly in the light curve was densely observed by ground-based-survey and follow-up groups, and it was found to be explained by a planetary lens with a planet/host mass ratio of $q=7.0\times {10}^{-4}$ from the light-curve modeling. The ground-only and Spitzer-"only" data each provide very strong one-dimensional (1D) constraints on the 2D microlens parallax vector ${{\boldsymbol{\pi }}}_{{\rm{E}}}$ . When combined, these yield a precise measurement of ${{\boldsymbol{\pi }}}_{{\rm{E}}}$ and of the masses of the host ${M}_{\mathrm{host}}=0.56\pm 0.07\,{M}_{\odot }$ and planet Mplanet = 0.41 ± 0.05 MJup. The system lies at a distance DL = 5.2 ± 0.5 kpc from the Sun toward the Galactic bulge, and the host is more likely to be a disk population star according to the kinematics of the lens. The projected separation of the planet from the host is ${a}_{\perp }=3.5\pm 0.3\,\mathrm{au}$ (i.e., just over twice the snow line). The Galactic-disk kinematics are established in part from a precise measurement of the source proper motion based on OGLE-IV data. By contrast, the Gaia proper-motion measurement of the source suffers from a catastrophic 10σ error.

Keywords: Gravitational microlensing, Gravitational microlensing exoplanet detection
WIYN Open Cluster Study. LXXXI. Caught in the Act? The Peculiar Red Giant NGC 2243-W2135. High-dispersion spectra for giants through turnoff stars in the Li 6708 Å region have been obtained and analyzed in the old, metal-deficient open cluster, NGC 2243. When combined with high-dispersion data from other surveys, the cluster is found to contain a uniquely peculiar star at the luminosity level of the red clump. The giant is the reddest star at its luminosity, exhibits variability at a minimum 0.1 mag level on a timescale of days, is a single-lined, radial-velocity variable, and has $v\sin i$ between 35 and 40 km s-1. In sharp contrast with the majority of the red giant cluster members, the star has a detectable Li abundance, potentially as high or higher than other giants observed to date while at or just below the boundary normally adopted for Li-rich giants. The observed anomalies may be indicators of the underlying process by which the giant has achieved its unusual Li abundance, with a recent mass transfer episode being the most probable within the currently limited constraints.

Keywords: Open star clusters
TIC 278956474: Two Close Binaries in One Young Quadruple System Identified by TESS. We have identified a quadruple system with two close eclipsing binaries in Transiting Exoplanet Survey Satellite (TESS) data. The object is unresolved in Gaia and appears as a single source at parallax 1.08 ± 0.01 mas. Both binaries have observable primary and secondary eclipses and were monitored throughout TESS Cycle 1 (sectors 1-13), falling within the TESS Continuous Viewing Zone. In one eclipsing binary (P = 5.488 days), the smaller star is completely occluded by the larger star during the secondary eclipse; in the other (P = 5.674 days) both eclipses are grazing. Using these data, spectroscopy, speckle photometry, spectral energy distribution analysis, and evolutionary stellar tracks, we have constrained the masses and radii of the four stars in the two eclipsing binaries. The Li I equivalent width indicates an age of 10-50 Myr and, with an outer period of ${858}_{-5}^{+7}$ days, our analysis indicates this is one of the most compact young 2 + 2 quadruple systems known.

Keywords: Close binary stars, Multiple stars, Young stellar objects, Eclipsing binary stars
Spectral Variability of VHS J1256-1257b from 1 to 5 μm. Multiwavelength time-resolved observations of rotationally modulated variability from brown dwarfs and giant exoplanets are the most effective method for constraining their heterogeneous atmospheric structures. In a companion paper, we reported the discovery of strong near-infrared variability in HST/WFC3/G141 light curves of the very red L-dwarf companion VHS J1256-1257b. In this paper, we present a follow-up 36 hr Spitzer/IRAC Channel 2 light curve together with an in-depth analysis of the Hubble space telescope (HST) and the Spitzer data. The combined data set provides time-resolved light curves of VHS1256b sampling 1.1 to 4.5 μm. The Spitzer light curve is best fit with a single sine wave with a period of 22.04 ± 0.05 hr and a peak-to-peak amplitude of 5.76 ± 0.04%. Combining the period with a previously measured projected rotational velocity ( $v\,\sin \,i$ ), we find that VHS1256b is most consistent with equatorial viewing geometry. The HST/G141+Spitzer spectral energy distribution favors a model with a ${T}_{\mathrm{eff}}$ of 1000 K and low surface gravity with disequilibrium chemistry. The spectral variability of VHS1256b is consistent with predictions from partly cloudy models, suggesting that heterogeneous clouds are the dominant source of the observed modulations. We find evidence at the 3.3σ level for amplitude variations within the 1.67 μm CH4 band, which is the first such detection for a variable L-dwarf. We compare the HST/G141 time-resolved spectra of three red L-dwarfs with high-amplitude near-infrared rotational modulations and find that although their time-averaged spectra are similar, their spectroscopic variabilities exhibit notable differences. This diversity reinforces the advantage of time-resolved spectroscopic observations for understanding the atmospheres of brown dwarfs and directly imaged exoplanets.

Keywords: Brown dwarfs, Time series analysis, Light curves, L dwarfs, Photometry, Spectrophotometry, Exoplanet atmospheres, Atmospheric variability