Sazuna/UAT_keywords huggingface dataset:
Transit Hunt for Young and Maturing Exoplanets (THYME). VIII. A Pleiades-age Association Harboring Two Transiting Planetary Systems from Kepler. Young planets provide a window into the early stages and evolution of planetary systems. Ideal planets for such research are in coeval associations, where the parent population can precisely determine their ages. We describe a young association (MELANGE-3) in the Kepler field, which harbors two transiting planetary systems (KOI-3876 and Kepler-970). We identify MELANGE-3 by searching for kinematic and spatial overdensities around Kepler planet hosts with high levels of lithium. To determine the age and membership of MELANGE-3, we combine new high-resolution spectra with archival light curves, velocities, and astrometry of stars near KOI-3876 spatially and kinematically. We use the resulting rotation sequence, lithium levels, and color-magnitude diagram of candidate members to confirm the presence of a coeval 105 ± 10 Myr population. MELANGE-3 may be part of the recently identified Theia 316 stream. For the two exoplanet systems, we revise the stellar and planetary parameters, taking into account the newly determined age. Fitting the 4.5 yr Kepler light curves, we find that KOI-3876b is a 2.0 ± 0.1 R ⊕ planet on a 19.58 day orbit, while Kepler-970 b is a 2.8 ± 0.2 R ⊕ planet on a 16.73 day orbit. KOI-3876 was previously flagged as an eclipsing binary, which we rule out using radial velocities from APOGEE and statistically validate the signal as planetary in origin. Given its overlap with the Kepler field, MELANGE-3 is valuable for studies of spot evolution on year timescales, and both planets contribute to the growing work on transiting planets in young stellar associations.

Keywords: Early stellar evolution, Transits, Stellar dynamics, Exoplanet evolution, Stellar associations, Stellar evolution
Chemical Abundances of Young Massive Clusters in NGC 1313. We analyze spectroscopic observations of five young massive clusters (YMCs) in the barred spiral galaxy NGC 1313 to obtain detailed abundances from their integrated light. Our sample of YMCs was observed with the X-shooter spectrograph on the Very Large Telescope. We make use of theoretical isochrones to generate synthetic integrated-light spectra, iterating on the individual elemental abundances until converging on the best fit to the observations. We measure abundance ratios for [Ca/Fe], [Ti/Fe], [Mg/Fe], [Cr/Fe], and [Ni/Fe]. We estimate an Fe abundance gradient of -0.124 ± 0.034 dex kpc-1, and a slightly shallower α gradient of -0.093 ± 0.009 dex kpc-1. This is in contrast to previous metallicity studies that focused on the gas-phase abundances, which have found NGC 1313 to be the highest-mass barred galaxy known not to have a radial abundance gradient. We propose that the gradient discrepancy between the different studies originates from the metallicity calibrations used to study the gas-phase abundances. We also observe an age-metallicity trend that supports a scenario of constant star formation throughout the galaxy, with a possible burst in star formation in the southwest region where YMC NGC 1313-379 is located. ∗ Based on observations made with ESO telescopes at the La Silla Paranal Observatory under program ID 084.B-0468(A).

Keywords: Stellar abundances, Young star clusters, Chemical abundances, Extragalactic astronomy, Star clusters
India's First Robotic Eye for Time-domain Astrophysics: The GROWTH-India Telescope. We present the design and performance of the GROWTH-India telescope, a 0.7 m robotic telescope dedicated to time-domain astronomy. The telescope is equipped with a 4k back-illuminated camera that gives a 0.°82 field of view and a sensitivity of m g' ~ 20.5 in 5 minute exposures. Custom software handles observatory operations: attaining high on-sky observing efficiencies (≳80%) and allowing rapid response to targets of opportunity. The data processing pipelines are capable of performing point-spread function photometry as well as image subtraction for transient searches. We also present an overview of the GROWTH-India telescope's contributions to the studies of gamma-ray bursts, the electromagnetic counterparts to gravitational wave sources, supernovae, novae, and solar system objects.

Keywords: CCD photometry, Optical astronomy, Astronomical detectors, Astronomical instrumentation, Time domain astronomy, Automated telescopes, Optical observatories
Ω<SUB>bar</SUB> in NGC 5597 from Very Large Array H I 21 cm Observations. We report Very Large Array B-configuration observations of the atomic hydrogen 21 cm line emission from the barred disk galaxy NGC 5597 at an angular resolution of ~ 7.″1 × 4.″2. Using the resonance method, and assuming the ratio of the corotation radius to the semimajor axis of the stellar bar is unity ( ${ \mathcal R }\equiv {R}_{\mathrm{CR}}/{a}_{\mathrm{bar}}=1$ ), we estimate the angular pattern speed of the stellar bar to be, Ωbar ~ 15.3 km s-1 kpc-1. This constant value for Ωbar crosses Ωgas + κ(R)/4 at a distance ~6.73 kpc, which would correspond to the spatial location of the north spiral structure near an outer m = 4 resonance. This value of Ωbar is similar to the values estimated for other bright nearby barred galaxies that exhibit circumnuclear rings (near inner Lindblad resonance) or outer rings (near outer Lindblad resonance).

Keywords: Barred spiral galaxies, Interstellar atomic gas
Implicit Biases in Transit Models Using Stellar Pseudo Density. The transit technique is responsible for the majority of exoplanet discoveries to date. Characterizing these planets involves careful modeling of their transit profiles. A common technique involves expressing the transit duration using a density-like parameter, $\tilde{\rho }$ , often called the "circular density." Most notably, the Kepler project-the largest analysis of transit light curves to date-adopted a linear prior on $\tilde{\rho }$ . Here, we show that such a prior biases measurements of impact parameter, b, due to the nonlinear relationship between $\tilde{\rho }$ and transit duration. This bias slightly favors low values (b ≲ 0.3) and strongly disfavors high values (b ≳ 0.7) unless the transit signal-to-noise ratio is sufficient to provide an independent constraint on b, a criterion that is not satisfied for the majority of Kepler planets. Planet-to-star radius ratio, r, is also biased due to r - b covariance. Consequently, the median Kepler DR25 target suffers a 1.6% systematic underestimate of r. We present a techniques for correcting these biases and for avoiding them in the first place.

Keywords: Astronomy data modeling, Bayesian statistics, Exoplanets, Light curves, Transit photometry
3D Orbital Architecture of a Dwarf Binary System and Its Planetary Companion. Because of the diversity of stellar masses and orbital sizes of binary systems and the complex interaction between star-star, star-planet, and planet-planet, it has been difficult to fully characterize the planetary systems associated with binary systems. Here, we report high-precision astrometric observations of the low-mass binary system GJ 896AB, revealing the presence of a Jupiter-like planetary companion (GJ 896Ab). The planetary companion is associated to the main star GJ 896A, with an estimated mass of 2.3 Jupiter masses and an orbit period of 284.4 days. A simultaneous analysis of the relative astrometric data obtained in the optical and infrared with several telescopes, and the absolute astrometric data obtained at radio wavelengths with the Very Long Baseline Array (VLBA), reveals, for the first time, the fully characterized three-dimensional (3D) orbital plane orientation of the binary system and the planetary companion. The planetary and binary orbits are found to be in a retrograde configuration and with a large mutual inclination angle (Φ = 148°) between both orbital planes. Characterizing the 3D orbital architecture of binary systems with planets is important in the context of planet formation, as it could reveal whether the systems were formed by disk fragmentation or turbulence fragmentation, as well as the origin of spin-orbit misalignment. Furthermore, as most stars are in binary or multiple systems, our understanding of systems such as this one will help to further understand the phenomenon of planetary formation in general.

Keywords: Exoplanet dynamics, Astrometric exoplanet detection, Exoplanets, Exoplanet systems, Extrasolar gaseous planets
The Stability of Fiber Spectrographs in the Faint-source Regime. The use of optical fibers in astronomical instrumentation offers high-multiplex and light-gathering flexibility. However, with most previous fiber spectrographs optimized for large fields of view on modest-aperture telescopes, the performance of fibers in the context of faint targets on large telescopes remains largely untested. In this paper, we evaluate aspects of fiber stability, especially as they apply in the context of precision sky subtraction of faint sources at modest spectral resolution (R ~ 3000). After introducing a framework for describing potential systematic errors, we use publicly available data from existing instruments, including instrumentation used by the fourth-generation Sloan Digital Sky Survey's MaNGA project (MaNGA: Mapping Nearby Galaxies at Apache Point Observatory) and the Very Large Telescope's FLAMES: Fiber Large Array Multi Element Spectrograph. We isolate sources of fiber systematics and estimate the observed amplitude of persistent residuals as well as stochastic noise contributions resulting from changing fiber stresses. Comparing these levels against their impact on various sky subtraction schemes demonstrates that 0.1% precision sky subtraction with fiber instruments is possible. As a demonstration, we show that the MaNGA instrument can deliver 0.2% residuals on bright near-IR sky lines with nonlocal sky subtraction, if pseudo-slit limitations are addressed by allocating 50% of its fibers to sky. We further highlight recently published deep exposures that achieved a 1σ background level of 27.6 AB per square arc second, equivalent to a precision of 0.2% of the sky background continuum.

Keywords: Spectrometers, Sky noise, Astronomical instrumentation
The First Fall is the Hardest: The Importance of Peculiar Galaxy Dynamics at Infall Time for Tidal Stripping Acting at the Centers of Groups and Clusters. Using dark-matter-only N-body cosmological simulations, we measure the pericentre distance of dark matter halos on their first infall into group and cluster halos. We find that the pericentre distance (R peri) is an important parameter as it significantly affects the strength of tidal mass loss in dense environments, and likely other environmental mechanisms as well. We examine what determines the R peri value and find that, for most infallers, the dominant parameter is V ⊥, the tangential component of the orbital velocity as the halo enters the group/cluster halo for the first time. This means that the strength of tidal stripping acting near the cores of groups/clusters are strongly influenced by the external peculiar velocity field of the large-scale structure surrounding them, which differs between clusters and is sensitive to the mass ratio of infaller to host. We find that filament feeding also partially contributes to feeding in low-V ⊥ halos. Dynamical friction can also play a role in reducing R peri but this is only significant for those few relatively massive infallers (&gt;10% of the mass of their host). These results highlight how the response of galaxies to dense environments will sensitively depend on dynamics inherited from far outside those dense environments.

Keywords: Galaxy clusters, Galaxy dark matter halos, Large-scale structure of the universe, Orbits, Galaxy groups, N-body simulations
TOI-1452 b: SPIRou and TESS Reveal a Super-Earth in a Temperate Orbit Transiting an M4 Dwarf. Exploring the properties of exoplanets near or inside the radius valley provides insight on the transition from the rocky super-Earths to the larger, hydrogen-rich atmosphere mini-Neptunes. Here, we report the discovery of TOI-1452b, a transiting super-Earth (R p = 1.67 ± 0.07 R ⊕) in an 11.1 day temperate orbit (T eq = 326 ± 7 K) around the primary member (H = 10.0, T eff = 3185 ± 50 K) of a nearby visual-binary M dwarf. The transits were first detected by the Transiting Exoplanet Survey Satellite, then successfully isolated between the two 3.″2 companions with ground-based photometry from the Observatoire du Mont-Mégantic and MuSCAT3. The planetary nature of TOI-1452b was established through high-precision velocimetry with the near-infrared SPIRou spectropolarimeter as part of the ongoing SPIRou Legacy Survey. The measured planetary mass (4.8 ± 1.3 M ⊕) and inferred bulk density ( ${5.6}_{-1.6}^{+1.8}$ g cm-3) is suggestive of a rocky core surrounded by a volatile-rich envelope. More quantitatively, the mass and radius of TOI-1452b, combined with the stellar abundance of refractory elements (Fe, Mg, and Si) measured by SPIRou, is consistent with a core-mass fraction of 18% ± 6% and a water-mass fraction of ${22}_{-13}^{+21}$ %. The water world candidate TOI-1452b is a prime target for future atmospheric characterization with JWST, featuring a transmission spectroscopy metric similar to other well-known temperate small planets such as LHS 1140b and K2-18 b. The system is located near Webb's northern continuous viewing zone, implying that is can be followed at almost any moment of the year.

Keywords: M dwarf stars, Super Earths, Exoplanets
The TESS-Keck Survey. XIII. An Eccentric Hot Neptune with a Similar-mass Outer Companion around TOI-1272. We report the discovery of an eccentric hot Neptune and a non-transiting outer planet around TOI-1272. We identified the eccentricity of the inner planet, with an orbital period of 3.3 days and R p,b = 4.1 ± 0.2 R ⊕, based on a mismatch between the observed transit duration and the expected duration for a circular orbit. Using ground-based radial velocity (RV) measurements from the HIRES instrument at the Keck Observatory, we measured the mass of TOI-1272b to be M p,b = 25 ± 2 M ⊕. We also confirmed a high eccentricity of e  b  = 0.34 ± 0.06, placing TOI-1272b among the most eccentric well-characterized sub-Jovians. We used these RV measurements to also identify a non-transiting outer companion on an 8.7 day orbit with a similar mass of M p,c sin i = 27 ± 3 M ⊕ and e  c  ≲ 0.35. Dynamically stable planet-planet interactions have likely allowed TOI-1272b to avoid tidal eccentricity decay despite the short circularization timescale expected for a close-in eccentric Neptune. TOI-1272b also maintains an envelope mass fraction of f env ≈ 11% despite its high equilibrium temperature, implying that it may currently be undergoing photoevaporation. This planet joins a small population of short-period Neptune-like planets within the "Hot Neptune Desert" with a poorly understood formation pathway.

Keywords: Hot Neptunes, Eccentricity, Exoplanets
Recalculated Orbits Of Binaries and New Linear Solutions. In this paper we present recalculated orbital elements for nine binaries: EGG 2Aa, Ab, COU 1085, COU 1897, COU 1006, A 578Aa, Ab, A 1400, A 606, BU 984, and BU 992. Seven binaries have orbital periods longer than 100 yr, and two binaries have shorter orbital periods, 38 and 76 yr. Also, we present linear solutions determined for three double stars: COU 966, J838, and A 1247. In addition to the orbital elements for nine binaries, we give absolute magnitudes, spectral types, estimates of the masses, dynamical parallaxes, and for all 12 pairs the (O - C) residuals in θ and ρ.

Keywords: Fundamental parameters of stars, Visual binary stars
Probing Magnetic Fields in Protoplanetary Disk Atmospheres through Polarized Near-IR Light Scattered by Aligned Grains. Magnetic fields play essential roles in protoplanetary disks. Magnetic fields in the disk atmosphere are of particular interest, as they are connected to the wind-launching mechanism. In this work, we study the polarization of the light scattered off of magnetically aligned grains in the disk atmosphere, focusing on the deviation of the polarization orientation from the canonical azimuthal direction, which may be detectable in near-IR polarimetry with instruments such as VLT/SPHERE. We show with a simple disk model that the polarization can even be oriented along the radial (rather than azimuthal) direction, especially in highly inclined disks with toroidally dominated magnetic fields. This polarization reversal is caused by the anisotropy in the polarizability of aligned grains and is thus a telltale sign of such grains. We show that the near-IR light is scattered mostly by μm-sized grains or smaller at the τ = 1 surface and such grains can be magnetically aligned if they contain superparamagnetic inclusions. For comparison with observations, we generate synthetic maps of the ratios of U  ϕ /I and Q  ϕ /I, which can be used to infer the existence of (magnetically) aligned grains through a negative Q  ϕ  (polarization reversal) and/or a significant level of U  ϕ /I. We show that two features observed in the existing data, an asymmetric distribution of U  ϕ  with respect to the disk minor axis and a spatial distribution of U  ϕ  that is predominantly positive or negative, are incompatible with scattering by spherical grains in an axisymmetric disk. They provide indirect evidence for scattering by aligned nonspherical grains.

Keywords: Magnetic fields, Protoplanetary disks, Polarimetry
An ALMA 1.3 millimeter Search for Debris Disks around Solar-type Stars in the Pleiades. Millimeter emission from debris disks around stars of different ages provides constraints on the collisional evolution of planetesimals. We present ALMA 1.3 millimeter observations of a sample of 76 Solar-type stars in the ~115 Myr old Pleiades star cluster. These ALMA observations complement previous infrared observations of this sample by providing sensitivity to emission from circumstellar dust at lower temperatures, corresponding to debris at radii comparable to the Kuiper Belt and beyond. The observations obtain a beam size of 1.″5 (200 au) and a median rms noise of 54 μJy beam-1, which corresponds to a fractional luminosity L dust/L star ~ 10-4 for 40 K dust for a typical star in the sample. The ALMA images show no significant detections of the targeted stars. We interpret these limits in the context of a steady-state collisional cascade model for debris disk evolution that provides a good description of observations of the field population near the Sun but is not well-calibrated on younger populations. The ALMA nondetections of the Pleiades systems are compatible with the disk flux predictions of this model. We find no high fractional luminosity outliers from these ALMA data that could be associated with enhanced collisions resulting from activity not accounted for by steady-state evolution. However, we note that two systems (H II 1132 and HD 22680) show 24 μm excess much higher than the predictions of this model, perhaps due to unusually high dust production from dynamical events involving planets.

Keywords: Open star clusters, Debris disks
The GAPS Programme at TNG XXXIX. Multiple Molecular Species in the Atmosphere of the Warm Giant Planet WASP-80 b Unveiled at High Resolution with GIANO-B. Detections of molecules in the atmosphere of gas giant exoplanets allow us to investigate the physico-chemical properties of the atmospheres. Their inferred chemical composition is used as tracer of planet formation and evolution mechanisms. Currently, an increasing number of detections is showing a possible rich chemistry of the hotter gaseous planets, but whether this extends to cooler giants is still unknown. We observed four transits of WASP-80 b, a warm transiting giant planet orbiting a late-K dwarf star with the near-infrared GIANO-B spectrograph installed at the Telescopio Nazionale Galileo and performed high-resolution transmission spectroscopy analysis. We report the detection of several molecular species in its atmosphere. Combining the four nights and comparing our transmission spectrum to planetary atmosphere models containing the signature of individual molecules within the cross-correlation framework, we find the presence of H2O, CH4, NH3, and HCN with high significance, tentative detection of CO2, and inconclusive results for C2H2 and CO. A qualitative interpretation of these results, using physically motivated models, suggests an atmosphere consistent with solar composition and the presence of disequilibrium chemistry and we therefore recommend the inclusion of the latter in future modeling of sub-1000 K planets. ∗ Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated by the Fundación Galileo Galilei (FGG) of the Istituto Nazionale di Astrofisica (INAF) at the Observatorio del Roque de los Muchachos (La Palma, Canary Islands, Spain).

Keywords: High resolution spectroscopy, Exoplanet atmospheric composition , Molecular spectroscopy, Exoplanet astronomy, Exoplanet detection methods, Transit photometry, Exoplanet atmospheres
OGLE-2017-BLG-1038: A Possible Brown-dwarf Binary Revealed by Spitzer Microlensing Parallax. We report the analysis of microlensing event OGLE-2017-BLG-1038, observed by the Optical Gravitational Lensing Experiment, Korean Microlensing Telescope Network, and Spitzer telescopes. The event is caused by a giant source star in the Galactic Bulge passing over a large resonant binary-lens caustic. The availability of space-based data allows the full set of physical parameters to be calculated. However, there exists an eightfold degeneracy in the parallax measurement. The four best solutions correspond to very-low-mass binaries near ( ${M}_{1}={170}_{-50}^{+40}{M}_{J}$ and ${M}_{2}={110}_{-30}^{+20}{M}_{J}$ ), or well below ( ${M}_{1}={22.5}_{-0.4}^{+0.7}{M}_{J}$ and ${M}_{2}={13.3}_{-0.3}^{+0.4}{M}_{J}$ ) the boundary between stars and brown dwarfs. A conventional analysis, with scaled uncertainties for Spitzer data, implies a very-low-mass brown-dwarf binary lens at a distance of 2 kpc. Compensating for systematic Spitzer errors using a Gaussian process model suggests that a higher mass M-dwarf binary at 6 kpc is equally likely. A Bayesian comparison based on a galactic model favors the larger-mass solutions. We demonstrate how this degeneracy can be resolved within the next 10 years through infrared adaptive-optics imaging with a 40 m class telescope.

Keywords: Brown dwarfs, Binary lens microlensing, Satellite microlensing parallax, Gaussian Processes regression, Gravitational microlensing
Calibration of the IXPE Focal Plane X-Ray Polarimeters to Polarized Radiation. The Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small Explorer mission-in partnership with the Italian Space Agency-dedicated to X-ray polarimetry in the 2-8 keV energy band. The IXPE telescope comprises three grazing incidence mirror modules coupled to three detector units hosting each one a Gas Pixel Detector, a gas detector that allows measuring the polarization degree by using the photoelectric effect. A wide and accurate ground calibration was carried out on the IXPE Detector Units at INAF-IAPS, in Italy, where a dedicated facility was setup at this aim. In this paper, we present the results obtained from this calibration campaign to study the IXPE focal plane detector response to polarized radiation. In particular, we report on the modulation factor, which is the main parameter to estimate the sensitivity of a polarimeter.

Keywords: X-ray astronomy, Polarimetry