Sazuna/UAT_keywords huggingface dataset:
Measuring the Temperature of Starspots from Multi-filter Photometry. Using simultaneous multi-filter observations during the transit of an exoplanet around a K dwarf star, we determine the temperature of a starspot through modeling the radius and position with wavelength-dependent spot contrasts. We model the spot using the starspot modeling program STarSPot (STSP), which uses the transiting companion as a knife-edge probe of the stellar surface. The contrast of the spot, i.e., the ratio of the integrated flux of a darker spot region to the star's photosphere, is calculated for a range of filters and spot temperatures. We demonstrate this technique using simulated data of HAT-P-11, a K dwarf (T eff = 4780 K) with well-modeled starspot properties for which we obtained simultaneous multi-filter transits using Las Cumbres Observatory's MuSCAT3 instrument on the 2m telescope at Haleakala Observatory, which allows for simultaneous, multi-filter, diffuser-assisted high-precision photometry. We determine the average (i.e., a combination of penumbra and umbra) spot temperature for HAT-P-11's spot complexes is 4500 K ± 100 K using this technique. We also find for our set of filters that comparing the SDSS ${g}^{{\prime} }$ and ${i}^{{\prime} }$ filters maximizes the signal difference caused by a large spot in the transit. Thus, this technique allows for the determination of the average spot temperature using only one spot occultation in transit and can provide simultaneous information on the spot temperature and spot properties.

Keywords: Starspots, Multi-color photometry, Stellar activity
Dynamical Masses of 20 Asteroids Determined with Gaia DR3 Asteroid Observations. We combined the ground-based and Gaia Data Release 3 (DR3) asteroid observations to determine the masses of 20 asteroids with asteroid-asteroid close encounters. In order to take full advantage of the high-precision observations from Gaia, we use the Fisher information to select appropriate model parameters and the modified Encke's equation of motion to construct a dynamical model complete at the level of observation precision. With diameters from literature, bulk densities of 20 asteroids are derived. The results indicate that the utilization of Gaia DR3 provides substantial benefits in terms of improving mass precision. Among the 20 asteroids analyzed in our study, we find that 10 asteroids achieved a mass precision better than 5%, and 15 asteroids better than 10%.

Keywords: Celestial mechanics, Astrometry, Close encounters, Asteroids
exoMMR: A New Python Package to Confirm and Characterize Mean Motion Resonances. The study of orbital resonances allows for the constraint of planetary properties of compact systems. We can predict a system's resonances by observing the orbital periods of the planets, as planets in or near mean motion resonance (MMR) have period ratios that reduce to a ratio of small numbers. However, a period ratio near commensurability does not guarantee a resonance; we must study the system's dynamics and resonant angles to confirm resonance. Because resonances require in-depth study to confirm, and because two-body resonances require a measurement of the eccentricity vector which is quite challenging, very few resonant pairs or chains have been confirmed. We thus remain in the era of small-number statistics, not yet able to perform large population synthesis or informatics studies. To address this problem, we build a python package to find, confirm, and analyze MMRs, primarily through N-body simulations. We then analyze all near-resonant planets in the Kepler/K2 and TESS catalogs, confirming over 60 new resonant pairs and various new resonant chains. We additionally demonstrate the package's functionality and potential by characterizing the mass-eccentricity degeneracy of Kepler-80g, exploring the likelihood of an exterior giant planet in Kepler-80, and constraining the masses of planets in Kepler-305. We find that our methods overestimate the libration amplitudes of the resonant angles and struggle to confirm resonances in systems with more than three planets. We identify various systems that are likely resonant chains but that we are unable to confirm, and highlight next steps for exoplanetary resonances.

Keywords: Exoplanet dynamics, Exoplanet migration, Exoplanet structure
Variability in NGC 3201 Giant Stars. We present the analysis of 510 light curves in V and I bands of 255 giant stars in the globular cluster NGC 3201. Our aim is to expand the sample of new types of variables reported in a previous study. These variables show a short period (P  V  &lt; 0.6 day) and a low amplitude (A(V) &lt; 0.06 mag.). We first searched for variability using the generalized Lomb-Scargle and phase dispersion minimization periodograms of the sample, discarding 167 stars as non-variables. We then applied the significance test and reduced the sample to 88 giants, of which we classified 18 as possible variables, 11 as dubious, 41 as non-variables, and 18 as variables. We finally determined the cluster membership of this sample and grouped each star based on their light-curve shape. The discovered variables show periods in the range 0.2440 &lt; P  V  &lt; 0.5868 days and amplitudes between 0.010 &lt; A(V) &lt; 0.064 mag. Within the sample of 18 variable stars, we report the discovery of an object with a period P  V  = 0.3603 ± 0.0012 and amplitude A(V) = 0.703 ± 0.029 mag that shows a RR Lyrae ab-type light curve. Additionally, we report two RR Lyrae ab and c types with ultralow amplitude.

Keywords: Globular star clusters, Variable stars
Zwicky Transient Facility and Globular Clusters: The gr-band Period-Luminosity Relations for Mira Variables at Maximum Light and their Applications to Local Galaxies. Based on 14 Miras located in seven globular clusters, we derived the first gr-band period-luminosity (PL) at maximum light for the large-amplitude Mira variables using the multiyear light-curve data collected from the Zwicky Transient Facility (ZTF). Since Miras are red variables, we applied a color-term correction to subsets of ZTF light curves, and found that such corrections do not have a large impact on period determinations. We applied our derived PL relations to the known extragalactic Miras in five local galaxies (Sextans, Leo I, Leo II, NGC 6822 and IC 1613), and determined their Mira-based distances. We demonstrated that our PL relations can be applied to short-period (≲300 days) Miras, including those in the two most distant galaxies (NGC 6822 and IC 1613) in our sample even when only a portion of the light curves around maximum light have detections. We have also shown that the long-period extragalactic Miras do not follow the PL relations extrapolated to longer periods. Hence, our derived PL relations are only applicable to the short-period Miras, which will be discovered in abundance in local galaxies within the era of Vera C. Rubin Observatory's Legacy Survey of Space and Time.

Keywords: Globular star clusters, Sky surveys, Wide-field telescopes, Distance indicators, Mira variable stars
The Kinematics of the Young Stellar Population in the W5 Region of the Cassiopeia OB6 Association: Implication for the Formation Process of Stellar Associations. The star-forming region W5 is a major part of the Cassiopeia OB6 association. Its internal structure and kinematics may provide hints of the star formation process in this region. Here, we present a kinematic study of young stars in W5 using the Gaia data and our radial velocity data. A total 490 out of 2000 young stars are confirmed as members. Their spatial distribution shows that W5 is highly substructured. We identify a total of eight groups using the k-means clustering algorithm. There are three dense groups in the cavities of H II bubbles, and the other five sparse groups are distributed at the edges of the bubbles. The three dense groups have almost the same age (5 Myr) and show a pattern of expansion. The scale of their expansion is not large enough to account for the overall structure of W5. The three northern groups are, in fact, 3 Myr younger than the dense groups, which indicates independent star formation events. Only one of these groups shows the signature of feedback-driven star formation as its members move away from the eastern dense group. The other two groups might have formed in a spontaneous way. On the other hand, the properties of two southern groups are not understood as those of a coeval population. Their origins can be explained by dynamical ejection of stars and multiple star formation. Our results suggest that the substructures in W5 formed through multiple star-forming events in a giant molecular cloud.

Keywords: Stellar kinematics, Stellar dynamics, Star formation, Open star clusters, Stellar associations
PCAT-DE: Reconstructing Pointlike and Diffuse Signals in Astronomical Images Using Spatial and Spectral Information. Observational data from astronomical imaging surveys contain information about a variety of source populations and environments, and their complexity will increase substantially as telescopes become more sensitive. Even for existing observations, measuring the correlations between pointlike and diffuse emission can be crucial to correctly inferring the properties of any individual component. For this task, information is typically lost, because of conservative data cuts, aggressive filtering, or incomplete treatment of contaminated data. We present the code PCAT-DE, an extension of probabilistic cataloging, designed to simultaneously model pointlike and diffuse signals. This work incorporates both explicit spatial templates and a set of nonparametric Fourier component templates into a forward model of astronomical images, reducing the number of processing steps applied to the observed data. Using synthetic Herschel-SPIRE multiband observations, we demonstrate that point-source and diffuse emission can be reliably separated and measured. We present two applications of this model. For the first, we perform point-source detection/photometry in the presence of galactic cirrus and demonstrate that cosmic infrared background galaxy counts can be recovered in cases of significant contamination. In the second, we show that the spatially extended thermal Sunyaev-Zel'dovich effect signal can be reliably measured even when it is subdominant to the pointlike emission from individual galaxies.

Keywords: Astrostatistics tools, Bayesian statistics, Diffuse radiation, Markov chain Monte Carlo, Catalogs
Detecting and Characterizing Mg II Absorption in DESI Survey Validation Quasar Spectra. We present findings of the detection of Magnesium II (Mg II, λ = 2796, 2803 Å) absorbers from the early data release of the Dark Energy Spectroscopic Instrument (DESI). DESI is projected to obtain spectroscopy of approximately 3 million quasars (QSOs), of which over 99% are anticipated to be at redshifts greater than z &gt; 0.3, such that DESI would be able to observe an associated or intervening Mg II absorber illuminated by the background QSO. We have developed an autonomous supplementary spectral pipeline that detects these systems through an initial line-fitting process and then confirms the line properties using a Markov Chain Monte Carlo sampler. Based upon a visual inspection of the resulting systems, we estimate that this sample has a purity greater than 99%. We have also investigated the completeness of our sample in regard to both the signal-to-noise properties of the input spectra and the rest-frame equivalent width (W 0) of the absorber systems. From a parent catalog containing 83,207 quasars, we detect a total of 23,921 Mg II absorption systems following a series of quality cuts. Extrapolating from this occurrence rate of 28.8% implies a catalog at the completion of the five-year DESI survey that will contain over eight hundred thousand Mg II absorbers. The cataloging of these systems will enable significant further research because they carry information regarding circumgalactic medium environments, the distribution of intervening galaxies, and the growth of metallicity across the redshift range 0.3 ≤ z &lt; 2.5.

Keywords: Cosmology, AGN host galaxies, Galaxies, Galaxy distances, Sky surveys, Computational astronomy, Metal line absorbers, Large-scale structure of the universe, Quasars, Astronomy data analysis, Intergalactic medium, Catalogs
KMT-2022-BLG-2397: Brown Dwarf at the Upper Shore of the Einstein Desert. We measure the Einstein radius of the single-lens microlensing event KMT-2022-BLG-2397 to be θ E = 24.8 ± 3.6 μas, placing it at the upper shore of the Einstein Desert, 9 ≲ θ E/μas ≲ 25, between free-floating planets (FFPs) and bulge brown dwarfs (BDs). In contrast to the six BD (25 ≲ θ E ≲ 50) events presented by Gould et al. (2022), which all had giant-star source stars, KMT-2022-BLG-2397 has a dwarf-star source, with angular radius θ ast ~ 0.9 μas. This prompts us to study the relative utility of dwarf and giant sources for characterizing FFPs and BDs from finite-source point-lens (FSPL) microlensing events. We find "dwarfs" (including main-sequence stars and subgiants) are likely to yield twice as many θ E measurements for BDs and a comparable (but more difficult to quantify) improvement for FFPs. We show that neither current nor planned experiments will yield complete mass measurements of isolated bulge BDs, nor will any other planned experiment yield as many θ E measurements for these objects as the Korea Microlensing Telescope (KMT). Thus, the currently anticipated 10 yr KMT survey will remain the best way to study bulge BDs for several decades to come.

Keywords: Gravitational microlensing, Free floating planets, Gravitational microlensing exoplanet detection, Brown dwarfs
The Star Formation Across Cosmic Time (SFACT) Survey. II. The First Catalog from a New Narrowband Survey for Emission-line Objects. Star Formation Across Cosmic Time (SFACT) is a new narrowband (NB) survey designed to detect faint emission-line galaxies (ELGs) and QSOs over a broad range of redshifts. Here we present the first list of SFACT candidates from our pilot-study fields. Using the WIYN 3.5 m telescope, we are able to achieve good image quality with excellent depth and routinely detect ELGs to r = 25.0. The limiting line flux of the survey is ~1.0 × 10-16 erg s-1 cm-2. SFACT targets three primary emission lines: Hα, [O III] λ5007, and [O II] λ3727. The corresponding redshift windows allow for the detection of objects at z ~ 0-1. With a coverage of 1.50 deg2 in our three pilot-study fields, a total of 533 SFACT candidates have been detected (355 candidates deg-2). We detail the process by which these candidates are selected in an efficient and primarily automated manner, then tabulate accurate coordinates, broadband photometry, and NB fluxes for each source.

Keywords: Starburst galaxies, Blue compact dwarf galaxies, Spiral galaxies, Quasars, Surveys, Dwarf galaxies, Emission line galaxies, Galaxy abundances, Star formation, Galaxy evolution, Seyfert galaxies
The Star Formation Across Cosmic Time (SFACT) Survey. III. Spectroscopy of the Initial Catalog of Emission-line Objects. The Star Formation Across Cosmic Time (SFACT) survey is a new narrowband survey designed to detect emission-line galaxies (ELGs) and quasi-stellar objects (QSOs) over a wide range of redshifts in discrete redshift windows. The survey utilizes the WIYN 3.5 m telescope and the Hydra multifiber positioner to perform efficient follow-up spectroscopy on galaxies identified in the imaging part of the survey. Because the objects in the SFACT survey are selected by their strong emission lines, it is possible to obtain useful spectra for even the faintest of our sources (r ~ 25). Here, we present the 453 objects that have spectroscopic data from the three SFACT pilot-study fields, 415 of which are confirmed ELGs. The methodology for processing and measuring these data is outlined in this paper, and example spectra are displayed for each of the three primary emission lines used to detect objects in the survey (Hα, [O III]λ5007, and [O II]λ3727). Spectra of additional QSOs and nonprimary-emission-line detections are also shown as examples. The redshift distribution of the pilot-study sample is examined, and the ELGs are placed in different emission-line diagnostic diagrams in order to distinguish the star-forming galaxies from the active galactic nuclei.

Keywords: Dwarf irregular galaxies, Blue compact dwarf galaxies, Starburst galaxies, Quasars, Surveys, Emission line galaxies, LINER galaxies, Galaxy abundances, Seyfert galaxies, Galaxy evolution, Star formation, Galaxy spectroscopy
Astrometry and Photometry for ≈1000 L, T, and Y Dwarfs from the UKIRT Hemisphere Survey. We present the positions, proper motions, and near-infrared photometry for 966 known objects with spectral types later than M that were observed as part of the the UKIRT Hemisphere Survey (UHS). We augment the photometry and astrometry from UHS with information from Gaia DR3, Pan-STARRS DR2, and CatWISE 2020 to produce a database of homogeneous photometry and astrometry for this sample. The multi-epoch survey strategy of UHS allows us to determine the proper motions for most sources, with a median proper motion uncertainty of ~3.6 mas yr-1. Our UHS proper motion measurements are generally in good agreement with those from Gaia DR3, Pan-STARRS, and CatWISE 2020, with UHS proper motions typically more precise than those from CatWISE 2020 and Pan-STARRS but not Gaia DR3. We critically analyze the publicly available spectra for 406 members of this sample and provide updated near-infrared spectral types for ~100 objects. We determine typical colors as a function of spectral type and provide absolute magnitude versus spectral type relations for UHS J- and K-band photometry. Using newly determined proper motions, we highlight several objects of interest, such as objects with large tangential velocities, widely separated co-moving companions, and potential members of young nearby associations.

Keywords: Brown dwarfs, L dwarfs, Y dwarfs, Low mass stars, T dwarfs
Systematic KMTNet Planetary Anomaly Search. IX. Complete Sample of 2016 Prime-field Planets. As a part of the "Systematic KMTNet Planetary Anomaly Search" series, we report five new planets (namely, OGLE-2016-BLG-1635Lb, MOA-2016-BLG-532Lb, KMT-2016-BLG-0625Lb, OGLE-2016-BLG-1850Lb, and KMT-2016-BLG-1751Lb) and one planet candidate (KMT-2016-BLG-1855), which were found by searching 2016 KMTNet prime fields. These buried planets show a wide range of masses from Earth-class to super-Jupiter-class and are located in both the disk and the bulge. The ultimate goal of this series is to build a complete planet sample. Because our work provides a complementary sample to other planet detection methods, which have different detection sensitivities, our complete sample will help us to obtain a better understanding of planet demographics in our Galaxy.

Keywords: Gravitational microlensing exoplanet detection
Stable Fiber-illumination for Extremely Precise Radial Velocities with NEID. NEID is a high-resolution red-optical precision radial velocity (RV) spectrograph recently commissioned at the WIYN 3.5 m telescope at Kitt Peak National Observatory, Arizona, USA. NEID has an extremely stable environmental control system, and spans a wavelength range of 380-930 nm with two observing modes: a High Resolution mode at R ~ 112,000 for maximum RV precision, and a High Efficiency mode at R ~ 72,000 for faint targets. In this paper we present a detailed description of the components of NEID's optical fiber feed, which include the instrument, exposure meter, calibration system, and telescope fibers. Many parts of the optical fiber feed can lead to uncalibratable RV errors, which cannot be corrected for using a stable wavelength reference source. We show how these errors directly cascade down to performance requirements on the fiber feed and the scrambling system. We detail the design, assembly, and testing of each component. Designed and built from the bottom-up with a single-visit instrument precision requirement of 27 cm s-1, close attention is paid to the error contribution from each NEID subsystem. Finally, we include the lab and on-sky tests performed during instrument commissioning to test the illumination stability, and discuss the path to achieving the instrumental stability required to search for a true Earth twin around a solar-type star.

Keywords: Radial velocity, Spectrometers, Astronomical instrumentation, Exoplanets
Catalog of Integrated-light Star Cluster Light Curves in TESS. We present the first integrated-light, TESS-based light curves for star clusters in the Milky Way, Small Magellanic Cloud, and Large Magellanic Cloud. We explore the information encoded in these light curves, with particular emphasis on variability. We describe our publicly available package elk, which is designed to extract the light curves by applying principal component analysis to perform background light correction and incorporating corrections for TESS systematics, allowing us to detect variability on timescales shorter than ∼10 days. We perform a series of checks to ensure the quality of our light curves, removing observations where systematics are identified as dominant features, and deliver light curves for 348 previously cataloged open and globular clusters. Where TESS has observed a cluster in more than one observing sector, we provide separate light curves for each sector (for a total of 2204 light curves). We explore in detail the light curves of star clusters known to contain high-amplitude Cepheid and RR Lyrae variable stars, and we confirm that the variability of these known variables is still detectable when summed together with the light from thousands of other stars. We also demonstrate that even some low-amplitude stellar variability is preserved when integrating over a stellar population.

Keywords: Light curves, Variable stars, Time series analysis, Star clusters
Terrestrial- and Neptune-mass Free-Floating Planet Candidates from the MOA-II 9 yr Galactic Bulge Survey. We report the discoveries of low-mass free-floating planet (FFP) candidates from the analysis of 2006-2014 MOA-II Galactic bulge survey data. In this data set, we found 6111 microlensing candidates and identified a statistical sample consisting of 3535 high-quality single-lens events with Einstein radius crossing times in the range 0.057 &lt; t E/days &lt; 757, including 13 events that show clear finite-source effects with angular Einstein radii of 0.90 &lt; θ E/μas &lt; 332.54. Two of the 12 events with t E &lt; 1 day have significant finite-source effects, and one event, MOA-9y-5919, with t E = 0.057 ± 0.016 days and θ E = 0.90 ± 0.14 μas, is the second terrestrial-mass FFP candidate to date. A Bayesian analysis indicates a lens mass of ${0.75}_{-0.46}^{+1.23}$ M ⊕ for this event. The low detection efficiency for short-duration events implies a large population of low-mass FFPs. The microlensing detection efficiency for low-mass planet events depends on both the Einstein radius crossing times and the angular Einstein radii, so we have used image-level simulations to determine the detection efficiency dependence on both t E and θ E. This allows us to use a Galactic model to simulate the t E and θ E distribution of events produced by the known stellar populations and models of the FFP distribution that are fit to the data. Methods like this will be needed for the more precise FFP demographics determinations from Nancy Grace Roman Space Telescope data.

Keywords: Free floating planets, Gravitational microlensing exoplanet detection, Exoplanets