Sazuna/UAT_keywords huggingface dataset:
A Comparison of the Composition of Planets in Single-planet and Multiplanet Systems Orbiting M dwarfs. We investigate and compare the composition of M-dwarf planets in systems with only one known planet ("singles") to those residing in multiplanet systems ("multis") and the fundamental properties of their host stars. We restrict our analysis to planets with directly measured masses and radii, which comprise a total of 70 planets: 30 singles and 40 multis in 19 systems. We compare the bulk densities for the full sample, which includes planets ranging in size from 0.52 R ⊕ to 12.8 R ⊕, and find that single planets have significantly lower densities on average than multis, which we cannot attribute to selection biases. We compare the bulk densities normalized by an Earth model for planets with R  p  &lt; 6 R ⊕ and find that multis are also denser with 99% confidence. We calculate and compare the core/water mass fractions (CMF/WMF) of low-mass planets (M  p  &lt; 10 M ⊕) and find that the likely rocky multis (with R  p  &lt; 1.6 R ⊕) have lower CMFs than singles. We also compare the [Fe/H] metallicity and rotation period of all single-planet versus multiplanet host stars with such measurements in the literature and find that multiplanet hosts are significantly more metal-poor than those hosting a single planet. Moreover, we find that the host star metallicity decreases with increasing planet multiplicity. In contrast, we find only a modest difference in the rotation period. The significant differences in planetary composition and metallicity of the host stars point to different physical processes governing the formation of single-planet and multiplanet systems in M dwarfs.

Keywords: Exoplanet formation, Exoplanet systems
Flux Calibration of CHIME/FRB Intensity Data. Fast radio bursts (FRBs) are bright radio transients of microsecond to millisecond duration and unknown extragalactic origin. Central to the mystery of FRBs are their extremely high characteristic energies, which surpass the typical energies of other radio transients of similar duration, like Galactic pulsar and magnetar bursts, by orders of magnitude. Calibration of FRB-detecting telescopes for burst flux and fluence determination is crucial for FRB science, as these measurements enable studies of the FRB energy and brightness distribution in comparison to progenitor theories. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a radio interferometer of cylindrical design. This design leads to a high FRB detection rate but also leads to challenges for CHIME/FRB flux calibration. This paper presents a comprehensive review of these challenges, as well as the automated flux calibration software pipeline that was developed to calibrate bursts detected in the first CHIME/FRB catalog, consisting of 536 events detected between 2018 July 25 and 2019 July 1. We emphasize that, due to limitations in the localization of CHIME/FRB bursts, flux and fluence measurements produced by this pipeline are best interpreted as lower limits, with uncertainties on the limiting value.

Keywords: Calibration, Radio astronomy, Flux calibration, Radio transient sources
Speckle Interferometry at SOAR in 2022. Results of the speckle-interferometry observations at the 4.1 m SOuthern Astrophysical Research Telescope obtained during 2022 are presented: 2508 measurements of 1925 resolved pairs or subsystems and 785 nonresolutions of 611 targets; 26 pairs are resolved here for the first time. This work continues our long-term effort to monitor orbital motion in close binaries and hierarchical systems. A large number of orbits have been updated using these measurements.

Keywords: Interferometric binary stars
Detecting Multiplanetary Systems with Gravitational Microlensing and the Roman Space Telescope. It is plausible that most of the Stars in the Milky Way Galaxy, like the Sun, consist of planetary systems, instead of a single planet. Out of the estimately discovered 3980 planet-hosting stars, about 860 of them are known to be multiplanetary systems (as of 2023 June). Gravitational microlensing, which is the magnification in the light of a source star, due to a single or several lenses, has proven to be one of the most useful astrophysical phenomena with many applications. Until now, many extrasolar planets (exoplanets) have been discovered through binary microlensing, where the lens system consists of a star with one planet. In this paper, we discuss and explore the detection of multiplanetary systems that host two exoplanets via microlensing. This is done through the analysis and modeling of possible triple-lens configurations (one star and two planets) of a microlensing event. Furthermore, we examine different magnifications and caustic areas of the second planet, by comparing the magnification maps of triple and binary models in different settings. We also discuss the possibility of detecting the corresponding light curves of such planetary systems with the future implementation of the Nancy Grace Roman (Roman) Space Telescope and its Galactic Time Domain survey.

Keywords: Gravitational microlensing, Exoplanet detection methods, Gravitational microlensing exoplanet detection
ExoGemS High-resolution Transmission Spectroscopy of WASP-76b with GRACES. We present high-resolution transmission spectroscopy of WASP-76b with Gemini Remote Access to CFHT ESPaDOnS Spectrograph (GRACES)/Gemini North obtained as part of the ExoGemS survey. With a broad spectral range of 400-1050 nm and a relatively high resolution of ~66,000, these observations are particularly well suited to searching for atomic and molecular atmospheric species via the Doppler cross-correlation technique. We recover absorption features due to neutral iron (Fe I), sodium (Na I), and ionized calcium (Ca II) at high significance (&gt;5σ), and investigate possible atmospheric temperatures and wind speeds. We also report tentative (&gt;3σ) detections of Li I, K I, Cr I, and V I in the atmosphere of WASP-76b. Finally, we report nondetections of a number of other species, some of which have previously been detected with other instruments. Through model injection/recovery tests, we demonstrate that many of these species are not expected to be detected in our observations. These results allow us to place GRACES and the ExoGemS survey in context with other high-resolution optical spectrographs.

Keywords: Exoplanet atmospheric composition , Exoplanets, Hot Jupiters, Exoplanet atmospheric dynamics, Transmission spectroscopy, Extrasolar gaseous giant planets, Exoplanet atmospheres
Metrics for Optimizing Searches for Tidally Decaying Exoplanets. Tidal interactions between short-period exoplanets and their host stars drive orbital decay and have likely led to engulfment of planets by their stars. Precise transit timing surveys, with baselines now spanning decades for some planets, are directly detecting orbital decay for a handful of planets, with corroboration for planetary engulfment coming from independent lines of evidence. More than that, recent observations have perhaps even caught the moment of engulfment for one unfortunate planet. These portentous signs bolster prospects for ongoing surveys, but optimizing such a survey requires considering the astrophysical parameters that give rise to robust timing constraints and large tidal decay rates, as well as how best to schedule observations conducted over many years. The large number of possible targets means it is not feasible to continually observe all planets that might exhibit detectable tidal decay. In this study, we explore astrophysical and observational properties for a short-period exoplanet system that can maximize the likelihood for observing tidally driven transit timing variations. We consider several fiducial observational strategies and real exoplanet systems reported to exhibit decay. We show that moderately frequent (a few transits per year) observations may suffice to detect tidal decay within just a few years. Tidally driven timing variations take time to grow to detectable levels, so we estimate how long that growth takes as a function of timing uncertainties and tidal decay rate and provide thresholds for deciding that tidal decay has been detected.

Keywords: Exoplanet dynamics, Star-planet interactions, Transit timing variation method
Monitoring Hα Emission from the Wide-orbit Brown-dwarf Companion FU Tau B. Monitoring mass accretion onto substellar objects provides insights into the geometry of the accretion flows. We use the Lulin One-meter Telescope to monitor Hα emission from FU Tau B, a ~19 M Jup brown-dwarf companion at 5.″7 (719 au) from the host star, for six consecutive nights. This is the longest continuous Hα monitoring for a substellar companion near the deuterium-burning limit. We aim to investigate if accretion near the planetary regime could be rotationally modulated as suggested by magnetospheric accretion models. We find tentative evidence that Hα mildly varies on hourly and daily timescales, though our sensitivity is not sufficient to definitively establish any rotational modulation. No burst-like events are detected, implying that accretion onto FU Tau B is overall stable during the time baseline and sampling windows over which it was observed. The primary star FU Tau A also exhibits Hα variations over timescales from minutes to days. This program highlights the potential of monitoring accretion onto substellar objects with small telescopes.

Keywords: Accretion, Brown dwarfs, Lomb-Scargle periodogram, Stellar accretion, Time series analysis
Timescale of Stellar Feedback-driven Turbulence in the ISM: A Deep Dive into UGC 4305. Understanding the interplay of stellar feedback and turbulence in the interstellar medium (ISM) is essential to modeling the evolution of galaxies. To determine the timescales over which stellar feedback drives turbulence in the ISM, we performed a spatially resolved, multiwavelength study of the nearby star-forming dwarf galaxy UGC 4305. As indicators of turbulence on local scales (400 pc), we utilized ionized gas velocity dispersion derived from IFU Hα observations and atomic gas velocity dispersion and energy surface densities derived from H I synthesis observations with the Very Large Array. These indicators of turbulence were tested against star formation histories over the past 560 Myr derived from color-magnitude diagrams using Spearman's rank correlation coefficient. The strongest correlation identified at the 400 pc scale is between measures of H I turbulence and star formation 70-140 Myr ago. We repeated our analysis of UGC 4305's current turbulence and past star formation activity on multiple physical scales (~560 and 800 pc) to determine whether there are indications of changes in the correlation timescale with changes to the physical scale. No notable correlations were found at larger physical scales, emphasizing the importance of analyzing star formation-driven turbulence as a local phenomenon.

Keywords: Interstellar atomic gas, Optical astronomy, Dwarf galaxies, Interstellar medium, Extragalactic astronomy, Radio astronomy
OGLE-2016-BLG-1195 AO: Lens, Companion to Lens or Source, or None of the Above?. We systematically investigate Vandorou et al.'s claim to have detected the host star of the low-mass-ratio (q &lt; 10-4) microlensing planet OGLE-2016-BLG-1195Lb, via Keck adaptive optics (AO) measurements Δt = 4.12 yr after the event's peak (t 0). If correct, this measurement would contradict the microlens-parallax measurement derived from Spitzer observations taken near t 0. We show that this host identification would be in 4σ conflict with the original ground-based relative lens-source proper-motion measurements. By contrast, Gould estimated a probability p = 10% that the "other star" resolved by single-epoch late-time AO would be a companion to the host or the microlensed source, which is much more probable than a 4σ statistical fluctuation. Independent of this proper-motion discrepancy, the kinematics of this host identification are substantially less probable than those of the Spitzer solution. Hence, this identification should not be accepted, pending additional observations that would either confirm or contradict it, which could be taken in 2023. Motivated by this tension, we present two additional investigations. We explore the possibility that Vandorou et al. identified the wrong "star" for their analysis. Astrometry of KMT and Keck images favors a star (or asterism) lying about 175 mas northwest of Vandorou et al.'s star. We also present event parameters from a combined fit to all survey data, which yields a more precise mass ratio, q = (4.6 ± 0.4) × 10-5. Finally, we discuss the broader implications of minimizing such false positives for the first measurement of the planet mass function, which will become possible when AO on next-generation telescopes are applied to microlensing planets.

Keywords: Gravitational microlensing exoplanet detection, High-resolution microlensing event imaging, Satellite microlensing parallax
A Search for Extraterrestrial Technosignatures in Archival FAST Survey Data Using a New Procedure. The search for extraterrestrial intelligence (SETI) commensal surveys aim to scan the sky to find possible technosignatures from an extraterrestrial intelligence (ETI). The mitigation of radio frequency interference (RFI) is an important step, especially for the most sensitive Five-hundred-meter Aperture Spherical radio Telescope (FAST), which can detect more weak RFI. In this paper, we propose several new techniques for RFI mitigation and use our procedure to search for ETI signals from the archival data of FAST's first SETI commensal survey. We detect the persistent narrowband RFI by setting a threshold of the signals' sky separation and detect the drifting RFI (and potentially other types of RFI) using the Hough transform. We also use the clustering algorithms to remove more RFI and select candidates. The results of our procedure are compared to the earlier work on the same FAST data. We find that our methods, though relatively simpler in computation, remove more RFI (99.9912% compared to 99.9063% in the earlier work) but preserve the simulated ETI signals, except for those (5.1%) severely affected by the RFI. We also report more interesting candidate signals, about a dozen of which are new candidates that were not previously reported. In addition, we find that the proposed Hough transform method, with suitable parameters, also has the potential to remove the broadband RFI. We conclude that our methods can effectively remove the vast majority of the RFI while preserving and finding the candidate signals that we are interested in.

Keywords: Search for extraterrestrial intelligence, Radio astronomy, Astronomy data analysis
The \dot{M} -M <SUB>disk</SUB> Relationship for Herbig Ae/Be Stars: A Lifetime Problem for Disks with Low Masses?. The accretion of material from protoplanetary disks onto their central stars is a fundamental process in the evolution of these systems and a key diagnostic in constraining the disk lifetime. We analyze the relationship between the stellar accretion rate and the disk mass in 32 intermediate-mass Herbig Ae/Be systems and compare them to their lower-mass counterparts, T Tauri stars. We find that the $\dot{M}$ -M disk relationship for Herbig Ae/Be stars is largely flat at ~10-7 M ☉ yr-1 over 3 orders of magnitude in dust mass. While most of the sample follows the T Tauri trend, a subset of objects with high accretion rates and low dust masses are identified. These outliers (12 out of 32 sources) have an inferred disk lifetime of less than 0.01 Myr and are dominated by objects with low infrared excess. This outlier sample is likely identified in part by the bias in classifying Herbig Ae/Be stars, which requires evidence of accretion that can only be reliably measured above a rate of ~10-9 M ☉ yr-1 for these spectral types. If the disk masses are not underestimated and the accretion rates are not overestimated, this implies that these disks may be on the verge of dispersal, which may be due to efficient radial drift of material or outer disk depletion by photoevaporation and/or truncation by companions. This outlier sample likely represents a small subset of the larger young, intermediate-mass stellar population, the majority of which would have already stopped accreting and cleared their disks.

Keywords: Herbig Ae/Be stars, Pre-main sequence stars, Protoplanetary disks, Circumstellar disks
Stable Coronal X-Ray Emission over 20 yr of XZ Tau. XZ Tau AB is a frequently observed binary young stellar object in the Taurus Molecular Cloud; XZ Tau B has been classified as an EXOr object. We present new Chandra/HETG-ACIS-S observations of XZ Tau AB, complemented with variability monitoring of the system with XMM-Newton, to constrain the variability of this system and identify high-resolution line diagnostics to better understand the underlying mechanisms that produce the X-rays. We observe two flares with XMM-Newton but find that outside of these flares the coronal X-ray spectrum of XZ Tau AB is consistent over 20 yr of observations. We compare the ensemble of XZ Tau AB X-ray observations over time with the scatter across stars observed in point-in-time observations of the Orion Nebula Cluster and find that both overlap in terms of plasma properties, i.e., some of the scatter observed in the X-ray properties of stellar ensembles stems from intrinsic source variability.

Keywords: Young stellar objects, X-ray stars, Flare stars
EMU Detection of a Large and Low Surface Brightness Galactic SNR G288.8-6.3. We present the serendipitous detection of a new Galactic supernova remnant (SNR), G288.8-6.3, using data from the Australian Square Kilometre Array Pathfinder (ASKAP) Evolutionary Map of the Universe (EMU) survey. Using multifrequency analysis, we confirm this object as an evolved Galactic SNR at high Galactic latitude with low radio surface brightness and typical SNR spectral index of α = - 0.41 ± 0.12. To determine the magnetic field strength in SNR G288.8-6.3, we present the first derivation of the equipartition formulae for SNRs with spectral indices α &gt; - 0.5. The angular size is 1.°8 × 1.°6 (107.'6 × 98.'4), and we estimate that its intrinsic size is ~40 pc, which implies a distance of ~1.3 kpc and a position of ~140 pc above the Galactic plane. This is one of the largest in angular size and closest Galactic SNRs. Given its low radio surface brightness, we suggest that it is about 13,000 yr old.

Keywords: Supernova remnants, Radio astronomy
JWST/NIRCam Coronagraphy of the Young Planet-hosting Debris Disk AU Microscopii. High-contrast imaging of debris disk systems permits us to assess the composition and size distribution of circumstellar dust, to probe recent dynamical histories, and to directly detect and characterize embedded exoplanets. Observations of these systems in the infrared beyond 2-3 μm promise access to both extremely favorable planet contrasts and numerous scattered-light spectral features-but have typically been inhibited by the brightness of the sky at these wavelengths. We present coronagraphy of the AU Microscopii (AU Mic) system using JWST's Near Infrared Camera (NIRCam) in two filters spanning 3-5 μm. These data provide the first images of the system's famous debris disk at these wavelengths and permit additional constraints on its properties and morphology. Conducting a deep search for companions in these data, we do not identify any compelling candidates. However, with sensitivity sufficient to recover planets as small as ~0.1 Jupiter masses beyond ~2″ (~20 au) with 5σ confidence, these data place significant constraints on any massive companions that might still remain at large separations and provide additional context for the compact, multiplanet system orbiting very close-in. The observations presented here highlight NIRCam's unique capabilities for probing similar disks in this largely unexplored wavelength range, and they provide the deepest direct imaging constraints on wide-orbit giant planets in this very well-studied benchmark system.

Keywords: M dwarf stars, Exoplanet systems, Coronagraphic imaging, Direct imaging, Debris disks
Alert Classification for the ALeRCE Broker System: The Anomaly Detector. Astronomical broker systems, such as Automatic Learning for the Rapid Classification of Events (ALeRCE), are currently analyzing hundreds of thousands of alerts per night, opening up an opportunity to automatically detect anomalous unknown sources. In this work, we present the ALeRCE anomaly detector, composed of three outlier detection algorithms that aim to find transient, periodic, and stochastic anomalous sources within the Zwicky Transient Facility data stream. Our experimental framework consists of cross-validating six anomaly detection algorithms for each of these three classes using the ALeRCE light-curve features. Following the ALeRCE taxonomy, we consider four transient subclasses, five stochastic subclasses, and six periodic subclasses. We evaluate each algorithm by considering each subclass as the anomaly class. For transient and periodic sources the best performance is obtained by a modified version of the deep support vector data description neural network, while for stochastic sources the best results are obtained by calculating the reconstruction error of an autoencoder neural network. Including a visual inspection step for the 10 most promising candidates for each of the 15 ALeRCE subclasses, we detect 31 bogus candidates (i.e., those with photometry or processing issues) and seven potential astrophysical outliers that require follow-up observations for further analysis. 16 16 The code and the data needed to reproduce our results are publicly available at https://github.com/mperezcarrasco/AnomalyALeRCE.

Keywords: Surveys, Interdisciplinary astronomy, Astronomy data analysis
An Untargeted Survey of the Rotational Properties of Main-belt Asteroids using the Transiting Exoplanet Survey Satellite (TESS). We present photometric data for minor planets observed by the Transiting Exoplanet Survey Satellite during its Cycle 1 operations. In total, we extracted usable detections for 37,965 objects. We present an examination of the reliability of the rotation period and light-curve amplitudes derived from each object based upon the number of detections and the normalized Lomb-Scargle power of our period fitting and compare and contrast our results with previous similar works. We show that for objects with 200 or more photometric detections and a derived normalized, generalized Lomb-Scargle power greater than 0.2, we have an 85% confidence in that period; this encompasses 3492 rotation periods we consider to be highly reliable. We independently examine a series of periods first reported by Pál et al.; periods derived in both works found to have similar results should be considered reliable. Additionally, we demonstrate the need to properly account for the true proportion of slow rotators (P &gt; 100 hr) when inferring shape distributions from sparse photometry.

Keywords: Surveys, Asteroid rotation, Asteroids
The TESS-Keck Survey. XVI. Mass Measurements for 12 Planets in Eight Systems. With JWST's successful deployment and unexpectedly high fuel reserves, measuring the masses of sub-Neptunes transiting bright, nearby stars will soon become the bottleneck for characterizing the atmospheres of small exoplanets via transmission spectroscopy. Using a carefully curated target list and observations from more than 2 yr of APF-Levy and Keck-HIRES Doppler monitoring, the TESS-Keck Survey is working toward alleviating this pressure. Here we present mass measurements for 11 transiting planets in eight systems that are particularly suited to atmospheric follow-up with JWST. We also report the discovery and confirmation of a temperate super-Jovian-mass planet on a moderately eccentric orbit. The sample of eight host stars, which includes one subgiant, spans early-K to late-F spectral types (T eff = 5200-6200 K). We homogeneously derive planet parameters using a joint photometry and radial velocity modeling framework, discuss the planets' possible bulk compositions, and comment on their prospects for atmospheric characterization.

Keywords: Radial velocity, Exoplanets