Sazuna/UAT_keywords huggingface dataset:
Investigating Embedded Structures and Gas Kinematics in the Infrared-dark Cloud Hosting Bubble N59-North. We present a multiwavelength study of an extended area hosting the bubble N59-North to explore the physical processes driving massive star formation (MSF). The Spitzer 8 μm image reveals an elongated/filamentary infrared-dark cloud (length ∼28 pc) associated with N59-North, which contains several protostars and seven ATLASGAL dust clumps at the same distance. The existence of this filament is confirmed through 13CO and NH3 molecular line data in a velocity range of [95, 106] km s−1. All dust clumps satisfy Kauffmann and Pillai's condition for MSF. Using Spitzer 8 μm image, a new embedded hub-filament system candidate (C-HFS) is investigated toward the ATLASGAL clump, located near the filament's central region. MeerKAT 1.3 GHz continuum emission, detected for the first time toward C-HFS, reveals an ultracompact H II region driven by a B2-type star, suggesting an early stage of HFS with minimal feedback from the young massive star. The comparison of the position─velocity (PV) and position-PV (PPV) diagrams with existing theoretical models suggests that rotation, central collapse, and end-dominated collapse are not responsible for the observed gas motion in the filament. The PPV diagram indicates the expansion of N59-North by revealing blueshifted and redshifted gas velocities at the edge of the bubble. Based on comparisons with magnetohydrodynamic simulations, this study suggests that cloud─cloud collision (CCC) led to the formation of the filament, likely giving it a conical structure with gas converging toward its central region, where C-HFS is located. Overall, the study supports multi-scale filamentary mass accretion for MSF, likely triggered by CCC.

Keywords: Interstellar filaments, Massive stars, Star forming regions, Young stellar objects, Star formation, Interstellar objects
Revisiting Open Clusters within 200 pc in the Solar Neighborhood with Gaia DR3. In this study, we develop a membership identification method and apply it for 30 open clusters (OCs) within 200 pc of the Sun using astrometric data of Gaia DR3. By accounting for projection effects that distort apparent stellar motions, our approach converts astrometric data into accurate five-dimensional positions and velocities. This approach enables better identification of members in nearby OCs. We then compare our refined membership lists with previous catalogs, revealing more members in most OCs, but also the identification of elongated structures in Melotte 25 (Hyades), NGC 2632 (Praesepe), Melotte 111 (Coma Berenices), Platais 3, Melotte 22 (Pleiades), NGC 2451A, Platais 9, IC 2391, Platais 8, UPK 640, and HSC 2986, which we studied in detail. An analysis of the ages of their members reveals that the members within and outside of the tidal radius are distinctly coeval, further validating our methodology. This study suggests that for OCs in the solar neighborhood, correcting for the projection effect is very important for the identification of OC members.

Keywords: Open star clusters, Stellar evolutionary tracks, Star clusters
Stringent Limits on H<inline-formula> <mml:math><mml:msubsup><mml:mrow></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup></mml:math> </inline-formula> Emission from the Hot Jupiters WASP-80b and WASP-69b. Observations of auroras on exoplanets would provide numerous insights into planet–star systems, including potential detections of the planetary magnetic fields, constraints on host-star wind properties, and information on the thermal structures of planets. However, there have not yet been any discoveries of auroras on exoplanets. In this paper, we focus on the search for infrared auroral emission from the molecular ion H 3+ , which is common in the atmospheres of solar system planets Jupiter, Saturn, and Uranus. Using Keck/NIRSPEC high-resolution spectroscopy, we search for H 3+  emission from two hot Jupiters, WASP-80b and WASP-69b. We do not see any evidence of emission in the observed spectra when cross correlating with an H 3+  spectral model or when using an autocorrelation approach to search for any significant features. We therefore place upper limits on the total emission of 5.32 × 1018 W for WASP-80b and 1.64 × 1019 W for WASP-69b.These upper limits represent the most stringent limits to date and approach the regime of emission suspected from theoretical models.

Keywords: Exoplanets, Hot Jupiters, Exoplanet atmospheres
Open-source High-resolution Exoplanet Atmosphere Retrievals with POSEIDON. High-resolution spectroscopy (R &gt; 25,000) has opened new opportunities to characterize exoplanet atmospheres from the ground. By resolving individual lines in planetary emission and transmission spectra, one can sensitively probe the chemical inventory and temperature structure of exoplanets. However, a significant challenge to reliable and reproducible atmospheric inferences from high-resolution data sets has been the lack of open-source codes for high-resolution retrievals. Here, we present a unified high-resolution retrieval framework, for both emission and transmission spectroscopy, made publicly available within the open-source POSEIDON retrieval code. Our high-resolution retrieval framework is fast, accessible (no GPUs required), and well documented via Python notebooks. We validate our framework by reproducing previous emission retrievals of the hot Jupiter WASP-77Ab and transmission retrievals of the ultrahot Jupiter WASP-121b. Our results are broadly consistent with those of published works when making the same data detrending assumptions, but we demonstrate that user choices can subtly propagate into retrieved chemical abundances.

Keywords: High resolution spectroscopy, Exoplanet atmospheric composition , Open source software, Hot Jupiters, Exoplanet atmospheres
Auto-BUQ: Uncertainty Quantification for the Boundaries of Segmented Events. We present a new method to estimate the boundary of extended sources in high-energy photon lists and to quantify the uncertainty in the boundary. This method extends the graphed seeded region growing method developed by M. Fan et al. Here, we describe how an unambiguous boundary of a centrally concentrated astronomical source may be defined by first spatially segmenting the photon list, then forcibly merging the segments until only two segments—an extended source and its background—remain, and finally constructing a boundary as the connected outer edges of the Voronoi tessellation of the photons included in the source segment. The resulting boundary is then modeled using Fourier descriptors to generate a smooth curve, and this curve is bootstrapped to generate uncertainties. We apply the method to photon event lists obtained during the observations of galaxies NGC 2300 and Arp 299. We demonstrate how the derived extent and enclosed flux of NGC 2300 obtained with Chandra and XMM-Newton are comparable. We also show how complex internal structure, as in the case of Arp 299, may be subsumed to construct a compact boundary of the object.

Keywords: X-ray astronomy, Astronomy data modeling, Voronoi tessellation, Astrostatistics techniques, Extended radiation sources, Spatial point processes, Astrostatistics, X-ray sources, Astrostatistics strategies
Deep Synoptic Array Science: A 50 Mpc Fast Radio Burst Constrains the Mass of the Milky Way Circumgalactic Medium. We present the Deep Synoptic Array (DSA-110) discovery and interferometric localization of the so far nonrepeating FRB 20220319D. The FRB originates in a young, rapidly star-forming barred spiral galaxy, IRAS 02044+7048, at just 50 Mpc. Although the NE2001 and YMW16 models for the Galactic interstellar-medium (ISM) contribution to the DM of FRB 20220319D exceed its total observed DM, we show that uncertainties in these models accommodate an extragalactic origin for the burst. We derive a conservative upper limit on the DM contributed by the circumgalactic medium (CGM) of the Milky Way of 47.3 pc cm‑3, based on a pulsar nearby on the sky to FRB 20220319D that is used to estimate the ISM DM. This limit implies that the total Galactic CGM mass is &lt;1011M⊙, and that the baryonic mass of the Milky Way is ≲60% of the cosmological average given the total halo mass. More stringent albeit less conservative constraints are possible when the DMs of pulsars in the distant globular cluster M53 are additionally considered. Although our constraints are sensitive to possible anisotropy in the CGM and to the assumed form of the radial-density profile, they are not subject to uncertainties in the chemical and thermal properties of the CGM. Our results strongly support scenarios commonly predicted by galaxy-formation simulations wherein feedback processes expel baryonic matter from the halos of galaxies such as the Milky Way.

Keywords: Circumgalactic medium, Warm ionized medium, Star formation, Radio interferometers, Barred spiral galaxies, Radio transient sources
Search for the True Parent Body of the Phoenicid Meteor Shower. In 2024, Ďurišová et al. found that the meteor shower Phoenicids, IAU No. 254, code PHO, can originate in the nuclei of three comets, 46P/Wirtanen, 104P/Kowal 2, and 289P/Blanpain. The latter was suggested to be the parent body of the shower already in 1963 by Ridley. In this work, we model the meteoroid streams of all three comets and follow their dynamical evolution in course to reveal, which of the three comets is dynamically the most suitable parent body and if there is only a single parent or the stream might be fed with the particles released from more objects. It is a difficult task not only because these comets and particles released from them show an erratic dynamical evolution, but also because the Phoenicid shower is, according to the IAU Meteor Data Center List of Showers, currently represented by two significantly different solutions. We concluded that all three comets can contribute with the meteoroids to the Phoenicid stream. The dynamics of 289P's stream is mostly appropriate to fit the Phoenicid-shower solution AdNo = 1, but the nucleus of this comet is too small to explain the estimated total mass of the stream. The Phoenicids either occurred due to some sudden, but short term outbursts of the particles from the 289P's nucleus or the other two comets, especially 46P, are the further parent bodies. Our study also indicates that the recently discovered shower M2023-Y1 is most probably the third solution of the Phoenicids.

Keywords: Meteor streams, Short period comets, Comet dynamics, Meteor showers
An Unsupervised Machine Learning Approach to Identify Spectral Energy Distribution Outliers: Application to the S-PLUS DR4 Data. Identification of specific stellar populations using photometry for spectroscopic follow-up is a first step to confirm and better understand their nature. In this context, we present an unsupervised machine learning approach to identify candidates for spectroscopic follow-up using data from the Southern Photometric Local Universe Survey (S-PLUS). First, using an anomaly detection technique based on an autoencoder model, we select a large sample of objects (∼19,000) whose Spectral Energy Distribution is not well reconstructed by the model after training it on a well-behaved star sample. Then, we apply the t-distributed Stochastic Neighbor Embedding (t-SNE) algorithm to the 66 color measurements from S-PLUS, complemented by information from the SIMBAD database, to identify stellar populations. Our analysis reveals 69 carbon-rich star candidates that, based on their spatial and kinematic characteristics, may belong to the CH or carbon-enhanced metal-poor categories. Among these chemically peculiar candidates, we identify four as likely carbon dwarf stars. We show that it is feasible to identify three primary white-dwarf (WD) populations: WDs with hydrogen-dominated atmospheres, WDs with neutral helium-dominated atmospheres, and the WDs main sequence binaries (WD + MS). Furthermore, by using eROSITA X-ray data, we also highlight the identification of candidates for very active low-mass stars. Finally, we identified a large number of binary systems using the autoencoder model, but did not observe a clear association between the overdensities in the t-SNE map and their orbital properties.

Keywords: Binary stars, White dwarf stars, Carbon stars, Low mass stars, Chemically peculiar stars
Water Dissociation and Rotational Broadening in the Atmosphere of KELT-20 b from High-resolution Spectroscopy. We present atmospheric retrievals from Keck/KPIC Phase II observations of the ultrahot Jupiter (UHJ) KELT-20/MASCARA-2 b. Previous free retrievals of molecular abundances for UHJs have been impacted by significant model biases due to variations in vertical abundance profiles, which we address by including molecular dissociation into our retrieval framework as an additional free parameter. We measure the abundance of CO ( logCOMMR=‑2.5‑0.5+0.6 ) and obtain a lower limit on the abundance of H2O ( logH2OMMR=‑1.5‑1.0+0.8 , &gt;‑3.0 at 95% confidence) in the atmosphere of KELT-20 b. These abundances yield an atmospheric  C/O=0.1‑0.1+0.4  (C/O &lt; 0.9 at 95% confidence) and suggest a metallicity approximately solar to 10 × solar. H2O is dissociated at pressures below  logPH2O=‑1.2‑0.7+0.5  bar, roughly consistent with predictions from chemical equilibrium models, and suggesting that the retrieved composition is not a result of assumptions about the vertical mixing profiles. We also constrain the rotational velocity of KELT-20 b to  vsini=7.5±0.7  km s‑1, suggesting the presence of a jet comparable to the sound speed in the direction of the planet's rotation, assuming the actual rotation of the planet is tidally locked.

Keywords: High resolution spectroscopy, Exoplanet atmospheric composition , Hot Jupiters, Exoplanet atmospheres
A Swarm of WASP Planets: Nine Giant Planets Identified by the WASP Survey. The Wide Angle Search for Planets (WASP) survey provided some of the first transiting hot Jupiter candidates. With the addition of the Transiting Exoplanet Survey Satellite (TESS), many WASP planet candidates have now been revisited and given updated transit parameters. Here, we present nine transiting planets orbiting FGK stars that were identified as candidates by the WASP survey and found to have planetary masses via radial velocity measurements. Subsequent space-based photometry taken by TESS as well as ground-based photometric and spectroscopic measurements have been used to jointly analyze the planetary properties of WASP-102 b, WASP-116 b, WASP-149 b WASP-154 b, WASP-155 b, WASP-188 b, WASP-194 b/HAT-P-71 b, WASP-195 b, and WASP-197 b. These planets have radii between 0.9 RJup and 1.4 RJup, masses between 0.1 MJup and 1.5 MJup, and periods between 1.3 and 6.6 days.

Keywords: Exoplanets, Exoplanet systems, Hot Jupiters
Unveiling the Atmosphere of the Super-Jupiter HAT-P-14 b with JWST NIRISS and NIRSpec. We report the combined JWST Near Infrared Spectrograph (NIRSpec)/G395H and the Near Infrared Imager and Slitless Spectrograph (NIRISS)/Single Object Slitless Spectroscopy (SOSS) transmission spectrum of the transiting super-Jupiter HAT-P-14 b, from 0.60 to 5.14 μm. Initial analysis of these data reported a near-featureless spectrum at NIRSpec wavelengths range (2.87–5.14 μm) consistent with the small atmospheric scale height of the planet and unexplained bumps and wiggles at NIRISS wavelengths range (0.6–2.8 μm). Here, we produce a self-consistent spectrum of HAT-P-14 b's atmosphere with an up-to-date reduction. We detect H2O (3.09σ) both across NIRISS/SOSS wavelengths range and at the bluest end of NIRSpec/G395H as well as a gray cloud deck (1.90σ). We constrain the atmospheric metallicity of HAT-P-14 b to be roughly Solar, with [Fe/H]  =‑0.08‑0.98+0.89 , consistent with the planet mass–metallicity relationship. The differences compared to previous works are likely due to the improved STScI jwst pipeline, which highlights the need to reanalyze the early NIRISS/SOSS transiting exoplanet targets with the latest methods. As HAT-P-14 b is placed as the 805th best target for transmission spectroscopy according to Transmission Spectroscopy Metrics, our results showcase JWST's unparalleled photometric precision which can easily characterize a thousand exoplanets' atmospheres through transmission spectroscopy.

Keywords: Exoplanet atmospheric composition , Bayesian statistics, Exoplanets, Transmission spectroscopy, Exoplanet astronomy, James Webb Space Telescope, Exoplanet atmospheres
A Revised Density Estimate for the Largest Known Exoplanet, HAT-P-67 b. Low-density (ρp &lt; 0.1 g cm‑3) hot Saturns are expected to quickly (&lt;100 Myr) lose their atmospheres owing to stellar irradiation, explaining their rarity. HAT-P-67 b seems to be an exception, with ρp &lt; 0.09 g cm‑3 and maintaining its atmosphere to well after 1 Gyr. We present a photometric and spectroscopic follow-up of HAT-P-67 b to determine how it avoided mass loss. HAT-P-67 b orbits a V = 10.1 evolved F-type star in a 4.81-day orbit. We present new radial velocity observations of the system from the NEID spectrograph on the WIYN 3.5 m Telescope from a follow-up campaign robust to stellar activity. We characterize the activity using photometry and activity indicators, revealing a stellar rotation period (5.40 ± 0.09 days) near HAT-P-67 b's orbital period. We mitigate the stellar activity using a constrained quasi-periodic Gaussian process through a joint fit of archival ground-based photometry, TESS photometry, and our NEID observations, obtaining a planetary mass of Mp = 0.45 MJ ± 0.15 MJ. Combined with a radius measurement of Rp = 2.140 RJ ± 0.025 RJ, this yields a density of  ρp=0.061‑0.021+0.020gcm‑3 , making HAT-P-67 b the second-lowest-density hot giant known to date. We find that the recent evolution of the host star caused mass loss for HAT-P-67 b to only recently occur. The planet will be tidally disrupted/engulfed in ∼150–500 Myr, shortly after losing its atmosphere. With rapid atmospheric mass loss, a large helium leading tail, and upcoming observations with the Hubble Space Telescope, HAT-P-67 b is an exceptional target for future studies, for which an updated mass measurement provides important context.

Keywords: Exoplanets, Stellar activity, Exoplanet astronomy, Exoplanet tides, Radial velocity, Transit photometry, Extrasolar gaseous giant planets
The Milky Way Project MOBStIRS: Parameterizing Infrared Stellar-wind Bow Shock Morphologies with Citizen Science. Mass-loss influences stellar evolution, especially for massive stars with strong winds. Stellar wind bow shock nebulae driven by Galactic OB stars can be used to measure mass-loss rates ( Ṁ ). The standoff distance (R0) between the star and the bow shock is set by momentum flux balance between the stellar wind and the surrounding interstellar medium (ISM). We created the Milky Way Project: mass-loss rates for OB Stars driving infrared bow shocks (MOBStIRS) using the online Zooniverse citizen science platform. We enlisted several hundred students to measure R0 and two other projected shape parameters for 764 cataloged infrared bow shocks. MOBStIRS incorporated 1528 JPEG cutout images produced from Spitzer GLIMPSE and MIPSGAL survey data. Measurements were aggregated to compute shape parameters for each bow shock image deemed high quality by participants. The average statistical uncertainty on R0 is 12.5% but varies from &lt;5% to ∼40% among individual bow shocks, contributing significantly to the total error budget of  Ṁ . The derived nebular morphologies agree well with (magneto) hydrodynamic simulations of bow shocks driven by the winds of OB stars moving at Va = 10–40 km s‑1 with respect to the ambient ISM. A systematic correction to R0 to account for viewing angle appears unnecessary for computing  Ṁ . Slightly more than half of MOBStIRS bow shocks are asymmetric, which could indicate anisotropic stellar winds, ISM clumping on sub-pc scales, time-dependent instabilities, and/or misalignments between the local ISM magnetic field and the star-bow-shock axis.

Keywords: Massive stars, Stellar bow shocks, Stellar mass loss, Infrared astronomy, Educational software, Circumstellar dust
Multiple Outbursts of Halley-type Comet 12P/Pons–Brooks. We present optical observations of the Halley-type comet 12P/Pons–Brooks (12P) on its approach to perihelion. The comet was active even in the first observations at ∼8 au. Starting at ∼4 au, 12P exhibited an extraordinary series of outbursts, in which the brightness changed by a factor up to 100 and the coma morphology transformed under the action of radiation pressure into a distinctive "horned" appearance. Individual outburst dust masses are several ×109 kg, with kinetic energies ∼1014 J, release times ∼104 s, and effective power ∼1010 W. These properties are most consistent with, although do not definitively establish, an origin by the crystallization of amorphous water ice with the related release of trapped supervolatile gases. This interpretation is supported by the observation that the specific outburst energy and the specific crystallization energy are comparable (both ∼105 J kg‑1).

Keywords: Comet interiors, Comet nuclei, Short period comets, Long period comets, Comet volatiles
An Extremely Hot Pulsating Prewhite Dwarf from OGLE. We show that the blue 18.3 minutes variable object discovered in the Galactic disk by the OGLE-III survey and named OGLE-GD-WD-0001 is a pulsating prewhite dwarf of PG 1159 spectral type. With an effective temperature of about 160,000 K it is among the hottest known pulsators being located close to the blue edge of the GW Virginis instability strip. The long-term OGLE observations indicate that the object has a positive period change rate of about 5 × 10−10 s s−1 and thus already contracts. There are no traces of a planetary nebula around this star.

Keywords: Fundamental parameters of stars, White dwarf stars, Sky surveys, Pulsating variable stars
TESS Light Curve of the Interacting Binary W Serpentis. The unusal light curve of the massive eclipsing binary W Ser was recently observed with high S/N and fast cadence by the NASA TESS mission. The TESS light curve records two eclipses and relatively fast variations outside of the eclipses. The eclipse timings verify the period increase of the binary, and the period derivative implies a mass transfer rate in excess of 10‑5 M⊙ yr‑1. The light curve shows a fading trend from just after an eclipse until the start of the next eclipse. The brightest flux source in the system is the accretion torus surrounding the mass gainer star, and we argue that these orbital-phase related fadings are the result of the injection of cooler gas from the mass donor entering the outskirts of the accretion torus. There are cyclic variations in the out-of-eclipse sections of the light curve that vary on a 2.8 day timescale. This equals the orbital period for gas in the outer regions of the accretion torus, so the photometric variations are probably the result of transitory, overdense regions that form at the rim of the accretion torus.

Keywords: Eclipsing binary stars, Interacting binary stars