Sazuna/UAT_keywords huggingface dataset:
Retrieval Survey of Metals in Six Ultrahot Jupiters: Trends in Chemistry, Rain-out, Ionization, and Atmospheric Dynamics. Ground-based high-resolution spectroscopy (HRS) has detected numerous chemical species and atmospheric dynamics in exoplanets, most notably ultrahot Jupiters (UHJs). However, quantitative estimates on abundances have been challenging but are essential for accurate comparative characterization and to determine formation scenarios. In this work, we retrieve the atmospheres of six UHJs (WASP-76 b, MASCARA-4 b, MASCARA-2 b, WASP-121 b, HAT-P-70 b, and WASP-189 b) with ESPRESSO and HARPS-N/HARPS observations, exploring trends in eleven neutral species and dynamics. While Fe abundances agree well with stellar values, Mg, Ni, Cr, Mn, and V show more variation, highlighting the difficulty in using a single species as a proxy for metallicity. We find that Ca, Na, Ti, and TiO are underabundant, potentially due to ionization and/or nightside rain-out. Our retrievals also show that relative abundances between species are more robust, consistent with previous works. We perform spatially resolved and phase-resolved retrievals for WASP-76 b and WASP-121 b given their high signal-to-noise observations, and find the chemical abundances in each of the terminator regions are broadly consistent. We additionally constrain dynamics for our sample through Doppler shifts and broadening of the planetary signals during the primary eclipse, with median blueshifts between ~0.9 and 9.0 km s-1 due to day-night winds. Furthermore, we constrain spectroscopic masses for MASCARA-2 b and HAT-P-70 b consistent with their known upper limits, but we note that these may be biased due to degeneracies. This work highlights the importance of future HRS studies to further probe differences and trends between exoplanets.

Keywords: High resolution spectroscopy, Exoplanet atmospheric composition , Atmospheric dynamics, Extrasolar gaseous giant planets
High-resolution Observations of H I in the IC 63 Reflection Nebula. Photodissociation regions (PDRs), where the (far-)ultraviolet light from hot young stars interact with the gas in surrounding molecular clouds, provide laboratories for understanding the nature and role of feedback by star formation on the interstellar medium. While the general nature of PDRs is well understood-at least under simplified conditions-the detailed dynamics and chemistry of these regions, including gas clumping, evolution over time, etc., can be very complex. We present interferometric observations of the 21 cm atomic hydrogen line, combined with [C II] 158 μm observations, toward the nearby reflection nebula IC 63. We find a clumpy H I structure in the PDR, and a ring morphology for the H I emission at the tip of IC 63. We further unveil kinematic substructure, of the order of 1 km s-1, in the PDR layers and several legs that will disperse IC 63 in &lt;0.5 Myr. We find that the dynamics in the PDR explain the observed clumpy H I distribution and lack of a well-defined H I/H2 transition front. However, it is currently not possible to conclude whether H I self-absorption and nonequilibrium chemistry also contribute to this clumpy morphology and missing H I/H2 transition front.

Keywords: Interstellar medium, Interstellar clouds, Photodissociation regions
Observing Atmospheric Escape in Sub-Jovian Worlds with JWST. Hydrodynamic atmospheric escape is considered an important process that shapes the evolution of sub-Jovian exoplanets, particularly those with short orbital periods. The metastable He line in the near-infrared at 1.083 μm is a reliable tracer of atmospheric escape in hot exoplanets, with the advantage of being observable from the ground. However, observing escaping He in sub-Jovian planets has remained challenging due to the systematic effects and telluric contamination present in ground-based data. With the successful launch and operations of JWST, we now have access to extremely stable high-precision near-infrared spectrographs in space. Here we predict the observability of metastable He with JWST in two representative and previously well-studied warm Neptunes, GJ 436 b (T eq = 687 K, R p = 0.37 R J) and GJ 1214 b (T eq = 588 K, R p = 0.25 R J). Our simulated JWST observations for GJ 436 b demonstrate that a single transit with NIRSpec/G140H is sensitive to mass-loss rates that are two orders of magnitude lower than what is detectable from the ground. Our exercise for GJ 1214 b show that the best configuration to observe the relatively weak outflows of warm Neptunes with JWST is with NIRSpec/G140H, and that NIRSpec/G140M and NIRISS/SOSS are less optimal. Since none of these instrument configurations can spectrally resolve the planetary absorption, we conclude that the 1D isothermal Parker-wind approximation may not be sufficient for interpreting such observations. More sophisticated models are critical for breaking the degeneracy between outflow temperature and mass-loss rate for JWST measurements of metastable He.

Keywords: Infrared astronomy, Extrasolar gaseous planets, Exoplanet atmospheres, Planet hosting stars
Chemical Compositions Of Red Giant Stars in the Old Open Cluster NGC 7789. We have gathered optical-region spectra, derived model atmosphere parameters, and computed elemental abundances for 15 red giant stars in the open cluster NGC 7789. We focus on the light element group CNOLi that provides clues to evolutionary changes associated with internal fusion events and chemical mixing. We confirm and extend an early report that NGC 7789 stars 193 and 301 have anomalously large Li abundances, and that these values are apparently unconnected to any other elements' abundances in these stars. A companion study of He I λ10830 lines in both field stars and cluster members shows that star 301 has a strong He feature while star 193 does not. Possible explanations for the large Li abundances of these stars include helium flash-induced mixing events and binary interactions at some past or present times. In either case an internal eruption of energy could cause fresh synthesis of lithium via the Cameron-Fowler Berillyum transport mechanism. Rapid transport of lithium to the outer layers may have created significant chromospheric transient disturbances, producing enough helium ionization to allow for the strong λ10830 absorption in star 301.

Keywords: High resolution spectroscopy, Open star clusters, Chemically peculiar giant stars, Stellar atmospheres
Dynamical Mass of the Young Brown Dwarf Companion PZ Tel B. Dynamical masses of giant planets and brown dwarfs are critical tools for empirically validating substellar evolutionary models and their underlying assumptions. We present a measurement of the dynamical mass and an updated orbit of PZ Tel B, a young brown dwarf companion orbiting a late-G member of the β Pic moving group. PZ Tel A exhibits an astrometric acceleration between Hipparcos and Gaia EDR3, which enables the direct determination of the companion's mass. We have also acquired new Keck/NIRC2 adaptive optics imaging of the system, which increases the total baseline of relative astrometry to 15 yr. Our joint orbit fit yields a dynamical mass of ${27}_{-9}^{+25}\,{M}_{\mathrm{Jup}}$ , semimajor axis of ${27}_{-4}^{+14}\,\mathrm{au}$ , eccentricity of ${0.52}_{-0.10}^{+0.08}$ , and inclination of ${91.73}_{-0.32}^{{+0.36}^\circ} $ . The companion's mass is consistent within 1.1σ of predictions from four grids of hot-start evolutionary models. The joint orbit fit also indicates a more modest eccentricity of PZ Tel B than previous results. PZ Tel joins a small number of young (&lt;200 Myr) systems with benchmark substellar companions that have dynamical masses and precise ages from moving group membership.

Keywords: Brown dwarfs, Direct imaging, Astrometry, Orbit determination
KIC 7284688: A Solar-type Eclipsing Binary with Rapidly Varying O'Connell Effect. We present comprehensive photometric and spectroscopic study of the short-period eclipsing binary KIC 7284688 based on the Kepler, TESS, and LAMOST data. The radial-velocity analysis indicates that it is a triple-lined system composed of a nearly equal-mass binary plus a line-of-sight star. The masses and radii of the components in the binary are measured to be M 1 = 1.142 ± 0.020M ⊙, R 1 = 1.204 ± 0.051R ⊙, and M 2 = 1.119 ± 0.019M ⊙, R 2 = 1.149 ± 0.052R ⊙. In addition to the eclipses, the light curves of the binary exhibit exhibit rapidly changing O'Connell effect, namely the inequality in light maxima, which could be attributed to the asynchronous rotation of the starspots. We analyzed the variability in the data of light residuals, the difference between light maxima (Max.I-Max.II) as well as the epochs of light minima and determined a rotation period of 0.644 days. Moreover, we detected a quasiperiod with ~213 days from both the data of (Max.I-Max.II) and light times of minima, which is almost identical to the beat between the rotation period (~0.644 days) and the orbital period (~0.646 days). We conclude that the quasiperiodic variations of the O'Connell on the system are probably related to the starspot migration and this is a very rapid variation compared to the magnetic cycles with timescales ranging from years to decades.

Keywords: Eclipsing binary stars, Starspots, Stellar rotation
COSMOS2020: Exploring the Dawn of Quenching for Massive Galaxies at 3 &lt; z &lt; 5 with a New Color-selection Method. We select and characterize a sample of massive (log(M */M ☉) &gt; 10.6) quiescent galaxies (QGs) at 3 &lt; z &lt; 5 in the latest Cosmological Evolution Survey catalog (COSMOS2020). QGs are selected using a new rest-frame color-selection method, based on their probability of belonging to the quiescent group defined by a Gaussian mixture model (GMM) trained on rest-frame colors (NUV - U, U - V, V - J) of similarly massive galaxies at 2 &lt; z &lt; 3. We calculate the quiescent probability threshold above which a galaxy is classified as quiescent using simulated galaxies from the SHARK semi-analytical model. We find that, at z ≥ 3 in SHARK, the GMM/NUVU - VJ method outperforms classical rest-frame UVJ selection and is a viable alternative. We select galaxies as quiescent based on their probability in COSMOS2020 at 3 &lt; z &lt; 5, and compare the selected sample to both UVJ- and NUVrJ-selected samples. We find that, although the new selection matches UVJ and NUVrJ in number, the overlap between color selections is only ~50%-80%, implying that rest-frame color commonly used at lower-redshift selections cannot be equivalently used at z &gt; 3. We compute median rest-frame spectral energy distributions for our sample and find the median QG at 3 &lt; z &lt; 5 has a strong Balmer/4000 Å break, and residual NUV flux indicating recent quenching. We find the number densities of the entire quiescent population (including post-starbursts) more than doubles from 3.5 ± 2.2 × 10-6 Mpc-3 at 4 &lt; z &lt; 5 to 1.4 ± 0.4 × 10-5 Mpc-3 at 3 &lt; z &lt; 4, confirming that the onset of massive galaxy quenching occurs as early as 3 &lt; z &lt; 5.

Keywords: Gaussian mixture model, High-redshift galaxies, Quenched galaxies, Galaxy classification systems
An In-depth Look at TOI-3884b: A Super-Neptune Transiting an M4Dwarf with Persistent Starspot Crossings. We perform an in-depth analysis of the recently validated TOI-3884 system, an M4-dwarf star with a transiting super-Neptune. Using high-precision light curves obtained with the 3.5 m Apache Point Observatory and radial velocity observations with the Habitable-zone Planet Finder, we derive a planetary mass of ${32.6}_{-7.4}^{+7.3}\,{M}_{\oplus }$ and radius of 6.4 ± 0.2 R ⊕. We detect a distinct starspot crossing event occurring just after ingress and spanning half the transit for every transit. We determine this spot feature to be wavelength dependent with the amplitude and duration evolving slightly over time. Best-fit starspot models show that TOI-3884b possesses a misaligned (λ = 75° ± 10°) orbit that crosses a giant pole spot. This system presents a rare opportunity for studies into the nature of both a misaligned super-Neptune and spot evolution on an active mid-M dwarf.

Keywords: Exoplanet astronomy, Exoplanet detection methods, Exoplanets, Starspots
Updated Planetary Mass Constraints of the Young V1298 Tau System Using MAROON-X. The early K-type T-Tauri star, V1298 Tau (V = 10 mag, age ≈ 20-30 Myr) hosts four transiting planets with radii ranging from 4.9 to 9.6 R ⊕. The three inner planets have orbital periods of ≈8-24 days while the outer planet's period is poorly constrained by single transits observed with K2 and the Transiting Exoplanet Survey Satellite (TESS). Planets b, c, and d are proto-sub-Neptunes that may be undergoing significant mass loss. Depending on the stellar activity and planet masses, they are expected to evolve into super-Earths/sub-Neptunes that bound the radius valley. Here we present results of a joint transit and radial velocity (RV) modeling analysis, which includes recently obtained TESS photometry and MAROON-X RV measurements. Assuming circular orbits, we obtain a low-significance (≈2σ) RV detection of planet c, implying a mass of ${19.8}_{-8.9}^{+9.3}\,{M}_{\oplus }$ and a conservative 2σ upper limit of &lt;39 M ⊕. For planets b and d, we derive 2σ upper limits of M b &lt; 159 M ⊕ and M d &lt; 41 M ⊕, respectively. For planet e, plausible discrete periods of P e &gt; 55.4 days are ruled out at the 3σ level while seven solutions with 43.3 &lt; P e/d &lt; 55.4 are consistent with the most probable 46.768131 ± 000076 days solution within 3σ. Adopting the most probable solution yields a 2.6σ RV detection with a mass of 0.66 ± 0.26 M Jup. Comparing the updated mass and radius constraints with planetary evolution and interior structure models shows that planets b, d, and e are consistent with predictions for young gas-rich planets and that planet c is consistent with having a water-rich core with a substantial (~5% by mass) H2 envelope.

Keywords: Transits, Exoplanets, Radial velocity, Exoplanet systems, Exoplanet astronomy, Mini Neptunes
Predicting the Yield of Small Transiting Exoplanets around Mid-M and Ultracool Dwarfs in the Nancy Grace Roman Space Telescope Galactic Bulge Time Domain Survey. We simulate the yield of small (0.5-4.0 R ⊕) transiting exoplanets around single mid-M and ultracool dwarfs (UCDs) in the Nancy Grace Roman Space Telescope Galactic Bulge Time Domain Survey. We consider multiple approaches for simulating M3-T9 sources within the survey fields, including scaling local space densities and using Galactic stellar population synthesis models. These approaches independently predict ~100,000 single mid-M dwarfs and UCDs brighter than a Roman F146 magnitude of 21 that are within the survey fields. Assuming planet occurrence statistics previously measured for early-to-mid-M dwarfs, we predict that the survey will discover ${1347}_{-124}^{+208}$ small transiting planets around these sources, each to a significance of 7.1σ or greater. Significant departures from this prediction would test whether the occurrence rates of small planets increase or decrease around mid-M dwarfs and UCDs compared to early-M dwarfs. We predict the detection of ${13}_{-3}^{+4}$ habitable, terrestrial planets (R  p  &lt; 1.23 R ⊕) in the survey. However, atmospheric characterization of these planets will be challenging with current or near-future space telescope facilities due to the faintness of the host stars. Nevertheless, accurate statistics for the occurrence of small planets around mid-M dwarfs and UCDs will enable direct tests of predictions from planet formation theories and will determine our understanding of planet demographics around the objects at the bottom of the main sequence. This understanding is critical given the prevalence of such objects in our galaxy, whose planets may therefore comprise the bulk of the galactic census of exoplanets.

Keywords: Extrasolar rocky planets, M dwarf stars, Brown dwarfs, Surveys, Late-type dwarf stars, L dwarfs, Exoplanet astronomy, Transit photometry, Astronomical simulations, T dwarfs
Revised Properties and Dynamical History for the HD 17156 System. From the thousands of known exoplanets, those that transit bright host stars provide the greatest accessibility toward detailed system characterization. The first known such planets were generally discovered using the radial-velocity technique, then later found to transit. HD 17156b is particularly notable among these initial discoveries because it diverged from the typical hot-Jupiter population, occupying a 21.2 day eccentric (e = 0.68) orbit, offering preliminary insights into the evolution of planets in extreme orbits. Here we present new data for this system, including ground- and space-based photometry, radial velocities, and speckle imaging, that further constrain the system properties and stellar/planetary multiplicity. These data include photometry from the Transiting Exoplanet Survey Satellite that cover five transits of the known planet. We show that the system does not harbor any additional giant planets interior to 10 au. The lack of stellar companions and the age of the system indicate that the eccentricity of the known planet may have resulted from a previous planet-planet scattering event. We provide the results from dynamical simulations that suggest possible properties of an additional planet that culminated in ejection from the system, leaving a legacy of the observed high eccentricity for HD 17156b.

Keywords: Exoplanet dynamics, Exoplanets, Radial velocity, Exoplanet systems, Exoplanet astronomy, Photometry, Exoplanet detection methods
The DESI Bright Galaxy Survey: Final Target Selection, Design, and Validation. Over the next 5 yr, the Dark Energy Spectroscopic Instrument (DESI) will use 10 spectrographs with 5000 fibers on the 4 m Mayall Telescope at Kitt Peak National Observatory to conduct the first Stage IV dark energy galaxy survey. At z &lt; 0.6, the DESI Bright Galaxy Survey (BGS) will produce the most detailed map of the universe during the dark-energy-dominated epoch with redshifts of &gt;10 million galaxies spanning 14,000 deg2. In this work, we present and validate the final BGS target selection and survey design. From the Legacy Surveys, BGS will target an r &lt; 19.5 mag limited sample (BGS Bright), a fainter 19.5 &lt; r &lt; 20.175 color-selected sample (BGS Faint), and a smaller low-z quasar sample. BGS will observe these targets using exposure times scaled to achieve homogeneous completeness and cover the footprint three times. We use observations from the Survey Validation programs conducted prior to the main survey along with simulations to show that BGS can complete its strategy and make optimal use of "bright" time. BGS targets have stellar contamination &lt;1%, and their densities do not depend strongly on imaging properties. BGS Bright will achieve &gt;80% fiber assignment efficiency. Finally, BGS Bright and BGS Faint will achieve &gt;95% redshift success over any observing condition. BGS meets the requirements for an extensive range of scientific applications. BGS will yield the most precise baryon acoustic oscillation and redshift-space distortion measurements at z &lt; 0.4. It presents opportunities for new methods that require highly complete and dense samples (e.g., N-point statistics, multitracers). BGS further provides a powerful tool to study galaxy populations and the relations between galaxies and dark matter.

Keywords: Cosmology, Observational cosmology, Galactic and extragalactic astronomy, Spectrophotometry, Galaxy spectroscopy, Redshift surveys, Galaxies
Prediction of Planet Yields by the PRime-focus Infrared Microlensing Experiment Microlensing Survey. The PRime-focus Infrared Microlensing Experiment (PRIME) will be the first to conduct a dedicated near-infrared microlensing survey by using a 1.8 m telescope with a wide field of view of 1.45 deg2 at the South African Astronomical Observatory. The major goals of the PRIME microlensing survey are to measure the microlensing event rate in the inner Galactic bulge to help design the observing strategy for the exoplanet microlensing survey by the Nancy Grace Roman Space Telescope and to make a first statistical measurement of exoplanet demographics in the central bulge fields where optical observations are very difficult owing to the high extinction in these fields. Here we conduct a simulation of the PRIME microlensing survey to estimate its planet yields and determine the optimal survey strategy, using a Galactic model optimized for the inner Galactic bulge. In order to maximize the number of planet detections and the range of planet mass, we compare the planet yields among four observation strategies. Assuming the Cassan et al. mass function as modified by Penny et al., we predict that PRIME will detect planetary signals for 42-52 planets (1-2 planets with M  p  ≤ 1M ⊕, 22-25 planets with mass 1M ⊕ &lt; M  p  ≤ 100M ⊕, 19-25 planets 100M ⊕ &lt; M  p  ≤ 10, 000M ⊕), per year depending on the chosen observation strategy.

Keywords: Gravitational microlensing exoplanet detection, Galactic center, Galaxy structure, Galactic bulge, Gravitational microlensing, Near infrared astronomy
A 4-8 GHz Galactic Center Search for Periodic Technosignatures. Radio searches for extraterrestrial intelligence have mainly targeted the discovery of narrowband continuous-wave beacons and artificially dispersed broadband bursts. Periodic pulse trains, in comparison to the above technosignature morphologies, offer an energetically efficient means of interstellar transmission. A rotating beacon at the Galactic Center (GC), in particular, would be highly advantageous for galaxy-wide communications. Here, we present blipss, a CPU-based open-source software that uses a fast folding algorithm (FFA) to uncover channel-wide periodic signals in radio dynamic spectra. Running blipss on 4.5 hr of 4-8 GHz data gathered with the Robert C. Byrd Green Bank Telescope, we searched the central $6^{\prime} $ of our galaxy for kHz-wide signals with periods between 11 and 100 s and duty cycles (δ) between 10% and 50%. Our searches, to our knowledge, constitute the first FFA exploration for periodic alien technosignatures. We report a nondetection of channel-wide periodic signals in our data. Thus, we constrain the abundance of 4-8 GHz extraterrestrial transmitters of kHz-wide periodic pulsed signals to fewer than one in about 600,000 stars at the GC above a 7σ equivalent isotropic radiated power of ≈2 × 1018 W at δ ≃ 10%. From an astrophysics standpoint, blipss, with its utilization of a per-channel FFA, can enable the discovery of signals with exotic radio frequency sweeps departing from the standard cold plasma dispersion law.

Keywords: Period search , Technosignatures, Galactic center, Search for extraterrestrial intelligence