Sazuna/UAT_keywords huggingface dataset:
New Light Curves of LP133-373 Reveal Flaring, A Refined Period and an Initial Epoch. We present new CCD Johnson V and Cousins R photometric data on the eclipsing binary LP133-373. Analysis includes the detection of a flare event, eclipse timings and a refined period and initial epoch for the system. The new ephemeris for this system is T = 2452760.70523 ± 0.00045 + 1.6279850 ± 4.3805144 × 10-7 × e. Previous studies by others have mentioned period changes and radial velocity changes over time, so we continue to monitor LP133-373.

Keywords: Eclipsing binary stars, Binary stars, Detached binary stars
Using Concentration Offset to Analyze the Dependence of Galaxy Quenching on Morphology. Quenching is the process by which a galaxy's star formation ceases and it moves from being a blue star-forming to a red quiescent galaxy. Concentration has been shown to be a good indicator of this process; this paper uses ΔΣ1 (a concentration offset derived below) to observe how quenching differs between galaxy morphologies. We use Sloan Digital Sky Survey data to plot ΔSFR against ΔΣ1, with morphological classifications from Galaxy Zoo 2 and environmental classifications from Yang et al. We find a difference in the distributions of concentration offset between early- and late-types that is not observed with differing environmental conditions and so conclude that separating the two allows more insight into their individual quenching processes. Late-types are shown to follow a process of compaction before then quenching and this is consistent with a picture where they quench slower than the early-types.

Keywords: Galaxy quenching
Zodiacal Exoplanets in Time (ZEIT). XIV. He I Transit Spectroscopy of the 650 Myr Hyades Planet K2-136c. We report the non-detection of excess absorption in the 1083.2 nm line of neutral triplet helium during a transit of K2-136c, a 2.9R⊕ planet on a 17.3 days orbit around a K-type dwarf in the 650 Myr old Hyades cluster. We limit the equivalent width of any transit-associated absorption in the He I line to &lt;25 mÅ at 99% confidence.

Keywords: Exoplanet astronomy, Young star clusters, Exoplanet atmospheres
The Occurrence of Lanthanides in the Atmosphere of the A1 V Star HR 4138. Evidence is presented that lanthanides are present and overabundant in the atmosphere of the sharp-lined A1 V star HR 4138. This interesting object needs to be reclassified as a Chemically Peculiar star.

Keywords: Chemically peculiar stars, Chemical abundances
A Study of Central Peaks and Central Pits on the Moon and Vesta. Impact craters are present on all bodies in the solar system with many displaying complex interior morphologies such as central peaks and central pits. Central peaks form due to the uplift of material in the center of the crater during transient crater formation while central pit formation has been suggested to occur by a number of processes including impacts into a weaker target which may contain volatiles. Comparing central peaks and central pits on rocky bodies like the Moon and Vesta will provide information about the formation processes of these morphologies on volatile poor bodies. In this study, we surveyed 248 craters on the Moon and Vesta. Our study of these central pits and central peaks suggest that crustal strength may contribute to the formation of central pits on rocky bodies and supports the notion that volatiles may not contribute to the formation of central pits on rocky bodies.

Keywords: Lunar craters, Lunar maria, Vesta, Lunar highlands, Lunar impacts, Asteroid surfaces
Magnetic Fields in the Massive Star-forming Region GL 437. In this note, I report a R-band polarimetric study on a massive star-forming region GL 437 (a.k.a. AFGL 437) to infer the magnetic field (B-field) geometry of this region. The mean B-field in the diffused region, is found to be parallel to the extended cloud structure and the Galactic plane. I compared present optical polarization results with archival submm results adapted from Curran &amp; Chrysostomou. A flipped field geometry is seen in denser parts of GL 437 which is an interesting finding. An infrared source WK 34 embedded in the cloud is associated with a poorly collimated outflow. These outflows are parallel to the inner field orientation but misaligned with outer B-fields. An investigation of gas kinematics of this region will be carried out to understand if the gas motion have some role in changing the field geometry.

Keywords: Interstellar magnetic fields, Starlight polarization
Spectroscopy of the Proposed White Dwarf Pulsar ASASSN-V J205543.90+240033.5. We obtained spectra of ASASSN-V J205543.90+240033.5 (J2055), a system that shows photometric variations similar to the white dwarf (WD) pulsar AR Scorpii. Our spectra display a continuum rising steeply toward the blue as well as an array of emission lines. Resolved Balmer and Paschen lines are seen with Hα and Hβ having central absorption features. The strongest lines are unresolved C II, C III, and N III as well as doubly ionized helium. The spectra are similar to that of YY Hya, and suggest that J2055 is a post-common envelope binary consisting of a hot compact star irradiating the face of a secondary of unknown spectral type. Velocity variations detected from the emission lines confirm the binary nature of J2055. The origin of the 10 minutes photometric variation remains uncertain.

Keywords: Close binary stars, White dwarf stars, Common envelope evolution, Variable stars
HD 41004: A Photometric Sheep in Wolf's Clothing?. HD 41004 is an unusual multiple star/planet system. Recent TESS photometry revealed a striking 31 hr period, far too short for the slowly rotating K dwarf primary. Instead, the modulation likely is from the diminutive dM secondary, spun-up to synchronous rotation by its close-in brown dwarf companion, and suffering intense magnetic activity as a result. If so, the red dwarf is perhaps destined to someday return the favor by cannibalizing its substellar partner.

Keywords: Brown dwarfs, Exoplanets, Stellar activity
Second Timescale Photometry of the Very Fast Nova V1674 Her with Palomar Gattini-IR. We report second-timescale infrared photometry of the nova V1674 Her using Palomar Gattini-IR (PGIR). These observations constitute the first infrared and highest temporal resolution data (resolution of ≈0.84 s) of the nova reported to date. PGIR observed in this fast readout mode for more than an hour on three nights between 3 and 6 days after discovery. We searched for periodic variability using a Lomb-Scargle periodogram and did not detect anything down to a three sigma upper limit of 0.093 mag. This suggests that the periodic variability detected in the nova by Patterson et al. was lower by at least a factor of about 1.65 in the first week of the eruption.

Keywords: Light curves, Time domain astronomy, Classical novae
The Fleming Survey: High-cadence Survey for Variable Stars in the Northern Galactic Plane. We present first results from the Fleming Survey, a high-cadence search for variable stars in the northern Galactic Plane, conducted with the James Gregory Telescope in St Andrews (UK). After observing twelve fields, each over a timespan of 3-5 hr and with a cadence of 1 min, we identify 8 variable stars with clear periodic flux modulation in our lightcurves. Two of these are deemed to be δ Scuti pulsators, five are most likely eclipsing binaries. For most of our discoveries, the variability is known in the literature, but the exact period and shape of the lightcurve is not. This mini-survey demonstrates that high-cadence observations with small telescopes are a useful complement to ongoing and planned massive variability surveys.

Keywords: Surveys, Algol variable stars, W Ursae Majoris variable stars, Delta Cepheid variable stars, Eclipsing binary stars
Global Sky Models can Improve Flux Estimates in Pulsar and FRB Studies. It is commonplace in pulsar and fast radio burst literature to estimate sky temperature by frequency-scaling of the Haslam et al. 408 MHz map. I suggest that this practice should stop, in favor of using readily available global sky models of diffuse foregrounds. This practical change will improve accuracy of pulse flux estimates.

Keywords: Radio transient sources, Calibration, Flux calibration, Pulsars
A Shortcut to Calculate SPAM Limb-darkening Coefficients. We release a new grid of stellar limb-darkening coefficients (LDCs, using the quadratic, power-2 and claret-4 laws) and intensity profiles for the Kepler, U, B, V and R passbands, based on STAGGER model atmospheres. The data can be downloaded from Zenodo: https://doi.org/10.5281/zenodo.5593162. We compare the newly released LDCs, computed by ExoTETHyS, with previously published values, based on the same atmospheric models using a so-called "SPAM" procedure. The SPAM method relies on synthetic light curves in order to compute the LDCs that best represent the photometry of exoplanetary transits. We confirm that ExoTETHyS achieves the same objective with a much simpler algorithm.

Keywords: Exoplanet systems, Transmission spectroscopy, Limb darkening, Eclipsing binary stars, Transit photometry, Stellar atmospheres
No Redetections of blc1 in 39 hr of Reobservation Campaigns of Proxima Centauri. In 2019 April, radio observations of Proxima Centauri were performed with the Ultra-Wideband Low Receiver on the Parkes Telescope. A narrowband radio search of these data revealed a technosignature signal-of-interest reported as "blc1" at 982.002 MHz. After the initial discovery of blc1 in the data in 2020 October, we performed a series of reobservations over the next 6 months, totaling 39 hr of on-sky time. We do not redetect blc1, or find any other signals-of-interest, within ±1 MHz of 982.002 MHz in this data set. Taken in context, this null result implies that blc1 was transient radio frequency interference, makes it less consistent with a periodic transmission, and makes it less consistent with interstellar scintillation.

Keywords: Search for extraterrestrial intelligence, Technosignatures, Astrobiology, Radio astronomy
Identification of White Dwarfs from Gaia EDR3 via Spectra from LAMOST DR7. We cross-matched 1.3 million white dwarf (WD) candidates from Gaia EDR3 with spectral data from LAMOST DR7 within 3″. Applying machine learning described in our previous work, we spectroscopically identified 6190 WD objects after visual inspection. 32 detailed classes were adopted for them, including but not limited to DAB and DB+M. We estimated the atmospheric parameters for the DA and DB type WD using Levenberg-Marquardt least-squares algorithm. Finally, a catalog of WD spectra from LAMOST is provided online.

Keywords: White dwarf stars
QLP Data Release Notes 001: K2 + TESS Analysis. TESS will target the ecliptic plane in Sectors 42-46. These sectors overlap with campaigns from the K2 mission, providing a unique opportunity for multi-mission light curve analysis. This data release note describes the combined analysis of K2 and TESS light curves as part of the Quick-Look Pipeline procedure, which processes light curves for all targets in TESS Full-Frame Images down to TESS magnitude T = 13.5. We describe updates to our codebase, and the planet transit search, candidate triage, and report generation that are affected by this combined analysis.

Keywords: Exoplanet detection methods, Transit photometry, Exoplanets, Time series analysis
The Rapid Far-ultraviolet Variability of ET And and Its Rotational Period. Evidence is presented that the far-ultraviolet flux of ET And (A0Vp SiSr) recorded by the International Ultraviolet Explorer was variable over a timescale of about one hour on 1979 August 7. In contrast, the spectra taken over 9 hr on 1979 August 3 do not show any flux variability. This behavior is discussed using the light curve of ET And recently acquired with TESS. We also derive a refined rotational period, Prot = 1.618845 ± 0.000006 days, from the detrended TESS light curve.

Keywords: Chemically peculiar stars
Jules Verne's Formulation of the Fermi Question. Jules Verne's novel Around the Moon envisions the circumlunar flight of a crewed projectile around the lunar farside ending with a safe return to Earth. The novel is justifiably famous, partly because of certain parallels it contains to the U.S. Apollo program a century later. What is less appreciated is that the novel contains a rather direct statement of what would later become known as the Fermi Question or Fermi Paradox.

Keywords: History of astronomy, Astrobiology
What is Exceptional about Solar Activity in the Early Phase of Cycle 25?. Solar Cycle 25 began in 2019 December and has been progressing nominally since. However, a closely associated pair of strong active regions, NOAA 12786 and 12785, emerged in 2020 November. The greater, northern component, 12786, attained a maximum sunspot area of 1000 μHemi. The sudden, uncharacteristic emergence of such a large concentration of intense magnetic flux in the early phase of the solar cycle has not been seen in previous cycles. Although the active region pair survived for two Carrington rotations, it did not produce any X- or M-class flares. Here we remark on the evolution of NOAA 12786 and 12785, first in the Sun's invisible and subsequently the visible hemispheres, and compare the irradiance and other characteristic profiles it manifested in the early ascending phase of cycle 25 with those of previous solar cycles.

Keywords: Solar active region velocity fields, Solar flares, Solar active regions, Solar oscillations, Solar activity
New Spectropolarimetric Measurements of HD 144941. We report new spectropolarimetric measurements of the magnetic massive He-strong star HD 144941, which is the most extreme member of this class of stars in terms of surface helium abundance. Twelve epochs over a time span of 1.5 times the rotation period were observed with the FOcal Reducer/low dispersion Spectrograph 2 on the European Southern Observatory's Very Large Telescope in 2021 July and August, doubling the low-resolution spectropolarimetry data available for the star.

Keywords: Early-type stars, Massive stars, Stellar magnetic fields
To the Problem of the Properties of Saturn's Rings' Ice. We are trying to determine the properties of the ice of the rings of Saturn based on the model of the origin of the rings, taking into account the magnetic field of the planet, as well as by choosing a suitable ice of the Earth.

Keywords: Planetary rings
On the Correct Use of Gravity-darkening Coefficients in the JKTEBOP Eclipsing-binary Code. Users of the JKTEBOP code to solve the light curves of eclipsing binaries often confuse the gravity darkening coefficients, y(λ), with the bolometric gravity darkening exponents, β. JKTEBOP requires the wavelength-dependent coefficients. I show that the numerical values of y(λ) and β can be rather different, leading to potential biases in the solution if the wrong quantities are used.

Keywords: Eclipsing binary stars, Light curves
TESS Detection of Rotation in the A1V Star α Lacertae. The A1V star α Lacertae was observed by TESS in 2019 September and October. The short-cadence photometry reveals periodic variation at the 24.6 ppm level. The 0.708 day variation is consistent with rotational modulation seen in main sequence A stars, and implies an equatorial rotation velocity of 153 km s-1. With prior spectroscopic measurement of the rotational broadening of 128 km s-1, this indicates an inclination of the rotation axis of 57°. The first harmonic of this period is present in the data, along with a two non-commensurate periods of 0.763 and 0.257 day, suggesting spot modulation with different periods, perhaps indicating differential rotation with latitude. Follow-up spectroscopy and photometry of this bright (V = 3.77) star can place valuable constraints on differential rotation and spot formation and evolution in A stars.

Keywords: Starspots, Stellar rotation, A stars
X-Rays from V723 Mon are due to Optical Loading in Swift XRT. V723 Mon was recently reported to be hosting the nearest (d = 460 pc) candidate black hole by Jayasinghe et al. An X-ray detection was claimed based on deep Swift XRT observations with a luminosity of LX ≈ 8 × 1029 erg s-1 or LX/LEdd ≈ 10-9. Here we show that the X-ray photons detected by Swift XRT are due to optical loading from the bright (V = 8.3 mag) star. Using events in the 2-10 keV energy band, where optical loading does not strongly contribute, we find a 3σ upper-limit on the unabsorbed 2-10 keV X-ray flux of FX &lt; 2.8 × 10-14 erg cm-2 s-1, corresponding to a luminosity LX &lt; 7.2 × 1029 erg s-1 at a distance of 460 pc or LX/LEdd ≲ 2 × 10-9 for a M ≈ 3M⊙ black hole.

Keywords: Spectroscopic binary stars, Black holes
Contaminante: A Tool for Automatically Finding a Close-to-optimal Aperture for Transiting Signals in Kepler, K2, and TESS Data. Together, NASA's Kepler/K2 and TESS missions have produced image data and time-series of millions of stars. These data have been used to identify thousands of transiting planet candidates. Unfortunately, some transiting signals do not originate from the target of the mission, and instead originate from background or blended eclipsing binaries. Exoplanet candidates can be vetted by searching for evidence that a detected transiting signal originates outside of the aperture. Centroiding tests, such as those employed by the Kepler Pipeline, have proved useful for vetting exoplanet candidates which have been falsely identified due to background contamination. However, centroiding tests are not able to provide a light curve of the true transiting target, which is valuable for vetting the origin of the signal. We present the contaminante Python tool which, given Kepler/K2 or TESS data, automatically builds a pixel aperture (An aperture is defined as a contiguous selection of pixels in a stack of imagettes, known as a Target Pixel File.) that maximizes the transiting signal at a given period, transit mid point and duration. In this research note, we describe the procedure we use to determine that optimal aperture, and show a demonstration of the contaminante tool on a Kepler false positive.

Keywords: Exoplanets, Astronomy data analysis, Time series analysis
The Distribution of Silicon and Magnesium over the Surface of 21 Com. Inspection of 10 individual spectra taken over the 24 hr monitoring of 21 Com with International Ultraviolet Explorer on 1991 April 17 reveals variations of low excitation lines of Si II between rotational phases φ = 0.18 and φ = 0.65 of the 2 days period, suggesting a inhomogeneous repartition of silicon over the surface of 21 Com. The silicon lines are weaker at rotational phase φ = 0.18. More recent optical high resolution high signal-to-noise ELODIE spectra taken in 2004 April confirm the variations of silicon lines from phase φ = 0.99 to φ = 0.47. The synthesis of the optical Si II lines yields estimates of the abundances of silicon: 8 times solar at phase 0.99 and 10 times solar at phase 0.47. The large FUV variations of 21 Com appear then to be partly due to changes in the silicon line and continuous opacity as the star rotates. In contrast, the Mg II lines do not show convincing variations between the two rotational phases observed in the optical.

Keywords: Chemically peculiar stars, Chemical abundances
Vetting: A Stand-alone Tool for Finding Centroid Offsets in NASA Kepler, K2, and TESS, Alerting the Presence of Exoplanet False Positives. We present a simple, standalone implementation of a "centroid test" for NASA's Kepler, K2, and TESS missions. This test identifies significant changes in the centroid of a star during a transit or eclipse. A significant centroid shift can be used as evidence that a transiting signal is a "false positive", due to a background eclipsing source. This test produces a likelihood of a significant centroid offset during transit, and the spacial limit to which a contaminating object can be ruled out by the data. The tool to perform this test is packaged in vetting, a pip installable, open source Python package. In this note we discuss the procedure for creating a centroid test.

Keywords: Exoplanets, Astronomy data analysis, Time series analysis
Analysis of High-precision TESS Photometry of the Black Hole X-Ray Binary Cygnus X-1: Evidence of Intrinsic Variability of the Luminous Blue Supergiant Component. We report on Transiting Exoplanet Survey Satellite (TESS) high-precision photometry of the iconic non-eclipsing 5.60 days (O9.7Iab+black hole) binary Cygnus X-1. Previous ground-based photometry reveals low-amplitude (~0.04 mag) ellipsoidal light-variations that arise from the tidal (and rotational) distortion of the O9.7Iab companion. Additional small light-variations have also been reported by many observers. Short-cadence TESS photometry was conducted over ~27 days during 2019 July-August. The photometry shows the expected ~5.60 days binary ellipsoidal variations, but in addition ~0.01-0.03 mag complex quasi-periodic brightness variations. The observations were analyzed to investigate the underlying extra-binary variability. We also determined a new time of minimum light and calculated an updated period and light elements. The quasi-periodic, (non-binary) light-variations likely arise from the complex pulsations of the blue supergiant.

Keywords: X-ray binary stars, High mass x-ray binary stars, O supergiant stars, Stellar pulsations
Color Dependence of Planetary Transit Depths due to Large Starspots and Dust Clouds: Application to PTFO 8-8695. Although thousands of exoplanets have now been discovered, there is still a significant lack of observations of young planets only a few Myr old. Thus there is little direct evidence available to differentiate between various models of planet formation. The detection of planets of this age would provide much-needed data that could help constrain the planet formation process. To explore what transit observations of such planets may look like, we model the effects of large starspots and dust clouds on the depths of exoplanet transits across multiple wavelengths. We apply this model to the candidate planet PTFO 8-8695b, whose depths vary significantly across optical and infrared wavelengths. Our model shows that, while large starspots can significantly increase the color dependence of planetary transits, a combination of starspots and a large cloud surrounding the planet is required to reproduce the observed transit depths across four wavelengths.

Keywords: Starspots, Transit photometry, Exoplanets
On the Use of Evidence and Goodness-of-fit Metrics in Exoplanet Atmosphere Interpretation. In exoplanet atmosphere analyses, a suite of retrievals, with and without different chemical components, is often run, with forward models generated across their parameter space. I discuss here potential pitfalls in the interpretation of the statistics of such setups, suggesting a few simple tests to consider when interpreting their results.

Keywords: Exoplanet atmospheric composition , Astrostatistics
PRIMASS-L Spectra Bundle V1.0. PRIMASS-L, at the Small Bodies Node (SBN) of the NASA Planetary Data System (PDS), is a spectral library that contains the results of the PRIMitive Asteroids Spectroscopic Survey (PRIMASS). As of June 2021, this library gathers spectra of about 642 asteroids from 10 families and two groups of asteroids that had been sparsely studied before (85% of our targets did not have published spectra and only 40% had visible photometry). PRIMASS-L contains spectra from a variety of ground-based facilities, this survey is ongoing and is expected to contain about 800 spectra by the end of 2022.

Keywords: Asteroids
Asteroid Lightcurve Database (LCDB) Bundle V4.0. The asteroid lightcurve database (LCDB) is one of the more widely-used research tools for those doing research that compares and contrasts physical characteristics of asteroid spin axis rates, sizes, pole orientations, and/or taxonomic class - among others. The V4.0 release includes lightcurve photometry results for 0 targets. Each object has one to several dozen detailed records that contain results obtained by reviewing the literature.

Keywords: Comets, Asteroids