Sazuna/UAT_keywords huggingface dataset:
Clusters, Clumps, Dust, and Gas (CCDG) in NGC 1614: Benchmarking Cluster Demographics in Extreme Systems. Observations of young star clusters in a variety of galaxies have been used to constrain basic properties related to star formation, such as the fraction of stars found in clusters (Γ) and the shape of the cluster mass function (CMF). However, the results can depend heavily on the reliability of the cluster age-dating process and other assumptions. One of the biggest challenges for successful age-dating lies in breaking the age–reddening degeneracy, where older, dust-free clusters and young, reddened clusters can have similar broadband colors. While this degeneracy affects cluster populations in all galaxies, it is particularly challenging in systems with dusty, extreme star-forming environments. We study the cluster demographics in the luminous infrared galaxy NGC 1614 using Hubble Space Telescope imaging taken in eight optical–near-infrared passbands. For age-dating, we adopt a spectral energy distribution fitting process that limits the maximum allowed reddening by region and includes Hα photometry directly. We find that without these assumptions essentially all clusters in the dust-free UV-bright arm that should have ages ≈50–250 Myr are incorrectly assigned ages younger than 10 Myr. We find that this method greatly reduces the number of clusters in the youngest (τ &lt; 10 Myr) age bin and shows a fairly uniform distribution of massive clusters, the most massive being ≈few × 107 M ⊙. A maximum likelihood fit shows that the CMF is well fitted by a power law with an index of approximately ‑1.8, with no statistically significant high-mass cutoff. We calculate the fraction of stars born in clusters to be Γ1‑10 = 22.4% ± 5.7%. The fraction of stars in clusters decreases quickly over time, with Γ10‑100 = 4.5% ± 1.1% and Γ100‑400 = 1.7% ± 0.4%, suggesting that clusters dissolve rapidly over the first ∼0.5 Gyr. The decreasing fraction of stars in clusters is consistent with the declining shape observed for the cluster age distribution.

Keywords: Star clusters, Luminous infrared galaxies
The MDW Hα Sky Survey: Data Release 0. The Mittelman─di Cicco─Walker (MDW) Hα Sky Survey is an autonomously operated and ongoing all-sky imaging survey in the narrowband Hα wavelength. The survey was founded by amateur astronomers and is presented here in its first stage of refinement for rigorous scientific use. Each field is exposed through an Hα filter with a 3 nm bandwidth for a total of 4 hr, with a pixel scale of 3.″2. Here, we introduce the first Data Release of the MDW Hα Survey (Data Release 0, or DR0), spanning 238 fields in the region of Orion (∼3100 deg2). DR0 includes: calibrated mean fields, star-removed mean fields, a point-source catalog matched to Data Release 1 of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1) and the Isaac Newton Telescope Galactic Plane Survey (IGAPS), and mosaics. 3 3 DR0 components are available at http://mdw.astro.columbia.edu; the DR0 catalog can also be found on the AAS Journals Zenodo repository: doi:10.5281/zenodo.12747455. DR0 components are available at http://mdw.astro.columbia.edu; the DR0 catalog can also be found on the AAS Journals Zenodo repository: doi:10.5281/zenodo.12747455.

Keywords: Emission line stars, Surveys, Amateur astronomers, Flux calibration, Interstellar medium, H II regions, Catalogs
Potential Chromospheric Evaporation in the M Dwarf's Flare Triggered by Einstein Probe Mission. Although flares from late-type main-sequence stars have been frequently detected in the multiwavelength, the associated dynamical process has been rarely reported so far. Here, we report follow-up observations of an X-ray transient triggered by Wide-field X-ray Telescope onboard the Einstein Probe at UT08:45:08 in 2024, May 7. The photometry in multibands and time-resolved spectroscopy started at 3 hr and 7.5 hr after the trigger, which enables us to identify the transient as a flare of the M-dwarf 2MASS J12184187‑0609123. The bolometric energy released in the flare is estimated to be ∼1036 erg from its X-ray light curve. The Hα emission-line profile obtained at about 7 hr after the trigger shows an evident blue asymmetry with a maximum velocity of 200–250 km s‑1. The blue wing can be likely explained by the chromospheric temperature (cool) upflow associated with chromospheric evaporation, in which the mass of the evaporating plasma is estimated to be 1.2 × 1018 g. In addition, a prominence eruption with an estimated mass of 7 × 1015 g &lt; M p &lt; 7 × 1018 g cannot be entirely excluded.

Keywords: Stellar x-ray flares, Stellar chromospheres, Stellar flares, Spectroscopy, Late-type dwarf stars
Generating X-Ray Transit Profiles with Batman. We present an adaptation of the exoplanet transit model code BATMAN, in order to permit the generation of X-ray transits. Our underlying extended coronal model assumes an isothermal plasma that is radially symmetric. While this ignores the effect of bright, active regions, observations of transits in X-rays will require averaging across multiple epochs of data for the foreseeable future, significantly reducing the importance of more complex modeling. Our publicly available code successfully generates the predicted W-shaped transit profile in X-rays due to the optically thin nature of the emission, which concentrates the expected observational emission around the limb of the photospheric stellar disk. We provide some examples based on the best known X-ray transit target, HD 189733 b, and examine the effect of varying the planet size, coronal temperature, and impact parameter on the resulting transit profile. We also derived scaling relationships for how the overall transit detectability is affected by changing these parameters. Over most of the parameter space, we find that the detectability scales linearly with the cross-sectional area of the planet in X-rays. The relationship with increasing coronal temperature is less fixed, but averages out to a power law with slope ‑1/4 except when the impact parameter is high. Indeed, varying impact parameter has little effect on detectability at all until it approaches unity.

Keywords: X-ray astronomy, Transits, Exoplanets, Exoplanet astronomy, Exoplanet detection methods, Transit photometry, Stellar coronae
Correcting Turbulence-induced Errors in Fiber Positioning for the Dark Energy Spectroscopic Instrument. Highly multiplexed, robotic, fiber-fed spectroscopic surveys are observing tens of millions of stars and galaxies. For many systems, accurate positioning relies on imaging the fibers in the focal plane and feeding that information back to the robotic positioners to correct their positions. Inhomogeneities and turbulence in the air between the focal plane and the imaging camera can affect the measured positions of fibers, limiting the accuracy with which fibers can be placed on targets. For the Dark Energy Spectroscopic Instrument, we dramatically reduced the effect of turbulence on measurements of positioner locations in the focal plane by taking advantage of stationary positioners and the correlation function of the turbulence. We were able to reduce positioning errors from 7.3 to 3.5 μm, speeding the survey by 1.6% under typical conditions.

Keywords: Experimental techniques, Spectroscopy
A New Statistical Analysis of the Morphology of Spiral Galaxies. Morphology is the starting point for understanding galaxies. Elmegreen et al. classified spiral galaxies into flocculent, multiple-arm, and grand-design galaxies based on the regularity of their spiral arm structure. With the release of a vast number of clear spiral galaxy images from the Sloan Digital Sky Survey, we conducted a morphological classification of 5093 blue spiral galaxies. A statistical analysis of this sample shows that the fractions of flocculent, multiple-arm, and grand-design galaxies are 38% ± 1%, 59% ± 1%, and 3% ± 1%, respectively. Redshift has no obvious influence on this classification. However, as the bulge size becomes larger, the fraction of multiple-arm galaxies increases, while that of flocculent galaxies decreases. In addition, we performed a statistical analysis of 3958 galaxies with a clear spiral arm structure, finding that 82% of these galaxies have two arms in their inner regions. We also found that the majority (74%) of the barred spiral galaxies exhibit the characteristics of two inner spiral arms and multiple outer spiral arms, and there is no barred spiral galaxy in this work with four continuous spiral arms from the inner to the outer regions. These results highlight that the spiral arm structure of the Milky Way, according to the current mainstream view of a four-arm galaxy with continuous arms extending from the inner to outer regions, is quite unique. However, our findings align with the spiral morphology of the Milky Way proposed by Xu et al., in which case our Galaxy can be considered typical.

Keywords: Spiral arms, Galaxy structure, Milky Way Galaxy, Spiral galaxies
uGMRT Survey of EXoplanets Around M-dwarfs (GS-EXAM): Radio Observations of GJ 1151. Coherent radio emission with properties similar to planetary auroral signals has been reported from GJ 1151, a quiescent, slow-rotating mid-M star, by the LOFAR Two-meter (120–170 MHz) Sky Survey. The observed LOFAR emission is fairly bright at 0.89 mJy with 64% circular polarization, and the emission characteristics are consistent with the interaction between an Earth-sized planet with an orbital period of 1–5 days and the magnetic field of the host star. However, no short-period planet has been detected around GJ 1151. To confirm the reported radio emission caused by the putative planet around GJ 1151 and to investigate the nature of this emission, we carried out upgraded Giant Metrewave Radio Telescope observations of GJ 1151 at 150, 218, and 400 MHz over 33 hr across ten epochs. No emission was detected at any frequency. While at 150 and 218 MHz, nondetection could be due to the low sensitivity of our observations, at 400 MHz, the rms sensitivities achieved were sufficient to detect the emission observed with LOFAR at ∼20σ level. Our findings suggest that the radio emission is highly time variable, likely influenced by the star-planet system's phase and the host star's magnetic field. Additional observations below 170 MHz, at more frequent epochs (as the periodicity of the emission is unknown), especially during periods of high stellar magnetic field strength, are needed to confirm the emission.

Keywords: M dwarf stars, Star-planet interactions, Radio continuum emission
Formation of CN and CO Molecules in the Envelope of Nova V1391 Cas During the Near-maximum Phase. Moderate-resolution spectra (R ≈ 2700) of the classical nova V1391 Cas were obtained in the near-infrared wavelength range of 0.95–2.45 μm on UT 2020 August 14.41 using the Keck II telescope and the NIRES spectrograph. The spectral analysis revealed simultaneous detection of CO and CN molecular features. The CN red-system band was observed solely in absorption, while the CO first overtone bands, encompassing both 12CO and 13CO, displayed a combination of emission and absorption features at different velocities, resembling a P-Cygni profile. This specific CO profile is unprecedented in classical novae observations. Additionally, the negative velocity shifts in the absorption bands of both CN and CO were found to be consistent with each other.

Keywords: Classical novae
The SDSS-V Local Volume Mapper Telescope System. This paper presents the Local Volume Mapper (LVM) telescope system. LVM is one of three surveys that form the fifth generation of the Sloan Digital Sky Survey (SDSS-V), and it employs a coordinated network of four, 16 cm diameter telescopes feeding integral field units (IFUs) leading to three fiber spectrographs. One telescope hosts the science IFU, while two others observe adjacent fields to calibrate geocoronal emission. The fourth telescope makes rapid observations of bright stars to compensate for telluric absorption. The entrance slits of the spectrographs intersperse the fibers from all three types of telescope, producing truly simultaneous science and calibration exposures. We describe the final design of the telescope system and report on its construction, alignment and testing in the laboratory, as well as the integration, testing, commissioning, and actual on-sky performance at Las Campanas Observatory.

Keywords: Sky surveys, Wide-field telescopes, Astronomical instrumentation, Automated telescopes, Telescopes
No Evidence for a Metallicity-dependent Enhancement of Distant Giant Companions to Close-in Small Planets in the California Legacy Survey. Understanding the relationship between close-in small (CS) planets and distant giants (DGs) is central to understanding the formation of planetary systems like our own. Most studies of this connection have found evidence for a positive correlation, though significant statistical and systematic uncertainties remain due to differences in sample size, target selection bias, and even the definitions of CS and DG planets. Recently, M. L. Bryan &amp; E. J. Lee conducted a study of 184 stars hosting super-Earths (  or R = 1 − 4 R ⊕) to determine the effect of stellar metallicity on the prevalence of DG companions ( , a = 1−10 au). They found that such giants are twice as common in the presence of inner planets, but only in metal-rich systems: P(DG∣CS, [Fe/H] &gt; 0) =   versus P(DG∣[Fe/H] &gt; 0) =  . Further, they found that this correlation disappears for metal-poor stars: P(DG∣CS, [Fe/H] ≤ 0) =   versus P(DG∣[Fe/H] ≤ 0) =  . We conducted an analogous study to test whether this effect was present in the California Legacy Survey sample. Using the same planet definitions, we did not find evidence for an enhancement in metal-rich systems: P(DG∣CS, [Fe/H] &gt; 0) =   versus P(DG∣[Fe/H] &gt; 0) =  . We also found a 2σ tension between our conditional rate and a 2x enhancement. We brought our results into closer agreement with M. L. Bryan &amp; E. J. Lee by repeating our analysis with different planet definitions. For example, considering only CS planets with   and DG planets with   gives P(DG∣CS, [Fe/H] &gt; 0) =   and P(DG∣[Fe/H] &gt; 0) =  , consistent with a 2x enhancement. However, we find that this 2x enhancement is also present when we apply the same planet definitions to the overall sample, challenging the idea that metallicity is responsible. Our sample, though only ∼1/6 the size of M. L. Bryan &amp; E. J. Lee, was assembled and analyzed self-consistently. The discrepancy between our findings and theirs may arise from a variety of sources, underscoring the need for large exoplanet surveys to overcome both small number statistics and sample inhomogeneities.

Keywords: Super Earths, Extrasolar gaseous giant planets, Exoplanets, Astrostatistics
A Near-infrared Survey of Candidate Haumea Family Members. The Haumea family is the only known dynamical family in the trans-Neptunian region. To date, 10 family members have been unambiguously identified using near-infrared (NIR) spectral or photometric data in combination with their strong dynamical proximity and the rest of the family. In this work, we build off previous empirically constructed models of the family to identify 39 candidate family members and follow up on eight of them using the Hubble Space Telescope (HST) to measure their visible and NIR colors. Six of the candidates have strong water-ice absorption features—consistent with family membership. Based on these initial findings, our sample of 39 candidate family members should contain about 20 more water-rich objects. Combining the HST visible and NIR photometry with past results, we find no evidence for significant color heterogeneity within the family. Of the six new family members, two have Δv ∼ 300 m s‑1, well outside of the traditionally defined velocity dispersion limit of ∼150 m s‑1. As evidence suggests they are not affected by any of Neptune's resonances, we propose that these family members are the result of dynamical sculpting by Neptune during its outward migration. Further searches for far-flung family members will be able to further explore this hypothesis.

Keywords: Dynamical evolution, HST photometry, Trans-Neptunian objects
Leaning Sideways: VHS 1256−1257 b is a Super-Jupiter with a Uranus-like Obliquity. We constrain the angular momentum architecture of VHS J125601.92-125723.9, a 140 ± 20 Myr old hierarchical triple system composed of a low-mass binary and a widely separated planetary-mass companion, VHS 1256 b. VHS 1256 b has been a prime target for multiple characterization efforts, revealing the highest measured substellar photometric variability to date and the presence of silicate clouds and disequilibrium chemistry. Here we add a key piece to the characterization of this super-Jupiter on a Tatooine-like orbit: we measure its spin-axis tilt relative to its orbit, i.e., the obliquity of VHS 1256 b. We accomplish this by combining three measurements. We find a projected rotation rate   for VHS 1256 b using near-infrared high-resolution spectra from Gemini/IGRINS. Combining this with a published photometric rotation period indicates that the companion is viewed edge on, with a line-of-sight spin axis inclination of i p = 90° ± 18°. We refit available astrometry measurements to confirm an orbital inclination of   degrees. Taken together, VHS 1256 b has a large planetary obliquity of ψ = 90° ± 25°. In total, we have three measured angular momentum vectors for the system: the binary orbit normal, companion orbit normal, and companion spin axis. All three are misaligned with respect to each other. Although VHS 1256 b is tilted like Uranus, their origins are distinct. We rule out planet-like scenarios including collisions and spin─orbit resonances, and suggest that top-down formation via core/filament fragmentation is promising.

Keywords: High resolution spectroscopy, Exoplanet systems, Astrostatistics, Exoplanet evolution, Exoplanet formation
DIAmante TESS AutoRegressive Planet Search (DTARPS). III. Understanding the DTARPS-S Candidate Transiting Planet Catalogs. The DIAmante Transiting Exoplanet Sky Survey (TESS) AutoRegressive Planet Search (DTARPS) project, using novel statistical methods, has identified several hundred candidates for transiting planetary systems obtained from 0.9 million full-frame Image light curves obtained in the TESS Year 1 southern-hemisphere survey. Ten lines of evidence including limited reconnaissance spectroscopy indicate that approximately half are true planets rather than false positives. Here various population properties of these candidates are examined. Half of the DTARPS-S candidates are hot Neptunes, populating the "Neptune desert" found in Kepler-planet samples. The DTARPS-S samples also identify dozens of ultrashort-period planets with orbital periods down to 5 hr, high-priority systems for atmospheric transmission spectroscopy, and planets orbiting low-mass M stars. DTARPS-S methodology is sufficiently well characterized at each step so that preliminary planet occurrence rates can be estimated. Except for the increase in hot Neptunes, DTARPS-S planet occurrence rates are consistent with Kepler rates. Overall, DTARPS-S provides one of the most reliable and useful catalogs of TESS exoplanet candidates that can be used to to improve our understanding of various exoplanetary populations and astrophysical processes.

Keywords: Exoplanet catalogs, Light curve classification , Transits, Period search , Time domain astronomy, Exoplanet detection methods
BSN: The First Photometric Study of 10 Contact Binary Systems from the Northern and Southern Hemispheres. Photometric observations were made with standard filters in four observatories for 10 contact binary systems. We analyzed the orbital period variations of the systems and found that six of them show long-term changes. The increase in the orbital period of the J07, N65, and PU Vir systems is caused by mass transfer, and the reduction in the orbital period of the J05, LO Psc, and N49 systems is caused by the combination of angular momentum loss and mass transfer. The first light-curve analysis was performed with the PHysics Of Eclipsing BinariEs Python code and Markov Chain Monte Carlo. We discussed the accuracy of photometric mass ratio estimates for contact binary systems with total and partial eclipses compared to spectroscopic results. We also compared our mass ratio findings to a recent method that estimates mass ratios from the light curve's third derivative. Then, we also discussed this new mass ratio estimate method for photometric data. The systems' positions were displayed in 18 empirical parameter relationships. According to the light-curve analysis and estimation of absolute parameters, systems BE Mus, J07, J08, N49, and N65 are A subtypes, and the others are W subtypes.

Keywords: CCD photometry, Close binary stars, Fundamental parameters of stars, Astronomy data analysis, Contact binary stars
Searching for GEMS: TOI-6383Ab, a Giant Planet Transiting an M3-dwarf Star in a Binary System. We report on the discovery of a transiting giant planet around the 3500 K M3-dwarf star TOI-6383A located 172 pc from Earth. It was detected by the Transiting Exoplanet Survey Satellite and confirmed by a combination of ground-based follow-up photometry and precise radial velocity measurements. This planet has an orbital period of ∼1.791 days, a mass of 1.040 ± 0.094 M  J , and a radius of  , resulting in a mean bulk density of   g cm‑3. TOI-6383A has an M dwarf companion star, TOI-6383B, which has a stellar effective temperature of T eff ∼ 3100 K and a projected orbital separation of 3126 au. TOI-6383A is a low-mass dwarf star hosting a giant planet and is an intriguing object for planetary evolution studies due to its high planet-to-star mass ratio. This discovery is part of the Searching for Giant Exoplanets around M-dwarf Stars (GEMS) Survey, intending to provide robust and accurate estimates of the occurrence of GEMS and the statistics on their physical and orbital parameters. This paper presents an interesting addition to the small number of confirmed GEMS, particularly notable since its formation necessitates massive, dust-rich protoplanetary discs and high accretion efficiency (&gt;10%). *Based on observations obtained with the Hobby–Eberly Telescope (HET), which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Ludwig-Maximillians-Universitaet Muenchen, and Georg-August Universitaet Goettingen. The HET is named in honor of its principal benefactors, William P. Hobby and Robert E. Eberly.

Keywords: Detection, Multiple stars, Exoplanets, Radial velocity, Exoplanet astronomy, Planet hosting stars, Exoplanet detection methods, Exoplanet formation