Sazuna/UAT_keywords huggingface dataset:
On the Orbit of the Binary Brown Dwarf Companion GL229 Ba and Bb. The companion GL229B was recently resolved by Xuan et al. as a tight binary of two brown dwarfs (Ba and Bb) through VLTI-GRAVITY interferometry and Very Large Telescope-CRIRES+ radial velocity (RV) measurements. Here, we present Bayesian models of the interferometric and RV data in additional detail, along with an updated outer orbit of the brown dwarf pair about the primary. To create a model of the inner orbit with robust uncertainties, we apply kernel phases to the GRAVITY data, to address baseline redundancy in the raw closure phases. Using parallel tempering, we constrain the binary's orbit using only VLTI-GRAVITY data, despite each epoch having low visibility-plane coverage and/or signal-to-noise ratio (SNR). We demonstrate very good agreement between the VLTI-GRAVITY and CRIRES+ data sets and find that the inner binary has a period of 12.1346 ± 0.0011 days, an eccentricity of 0.2317 ± 0.0025, and a total mass of 71.0 ± 0.4 Mjup, with Ba and Bb having masses of 37.7 ± 1.1 Mjup and 33.4 ± 1.0Mjup, respectively. With new Keck/NIRC2 astrometry, we update the outer orbit of GL229B around the primary. We find a semimajor axis of 42.9+3.0─2.4 au, an eccentricity of 0.736 ± 0.014, and a total mass for B of 71.7 ± 0.6 Mjup, consistent with that derived from the inner orbit. We find a mutual inclination of 31° ± 2 5, below the threshold for Kozai─Lidov oscillations. The agreement on the mass of Ba+Bb between the inner and outer orbits is an important test of our ability to model the RV, astrometry, and Hipparcos─Gaia proper-motion anomaly. Our methodological advances in handling interferometric data with low SNR and sparse UV coverage will benefit future observations of rapidly orbiting companions with VLTI-GRAVITY.

Keywords: Brown dwarfs, Interferometers, Astrometry, Radial velocity, T dwarfs
Use the 4S (Signal-Safe Speckle Subtraction): Explainable Machine Learning Reveals the Giant Exoplanet AF Lep b in High-contrast Imaging Data from 2011. The main challenge of exoplanet high-contrast imaging (HCI) is to separate the signal of exoplanets from their host stars, which are many orders of magnitude brighter. HCI for ground-based observations is further exacerbated by speckle noise originating from perturbations in Earth's atmosphere and imperfections in the telescope optics. Various data postprocessing techniques are used to remove this speckle noise and reveal the faint planet signal. Often, however, a significant part of the planet signal is accidentally subtracted together with the noise. In the present work, we use explainable machine learning to investigate the reason for the loss of the planet signal for one of the most used postprocessing methods: principal component analysis (PCA). We find that PCA learns the shape of the telescope point-spread function for high numbers of PCA components. This representation of the noise captures not only the speckle noise but also the characteristic shape of the planet signal. Building on these insights, we develop a new postprocessing method (4S) that constrains the noise model to minimize this signal loss. We apply our model to 11 archival HCI data sets from the Very Large Telescope NACO instrument in the L' band and find that our model consistently outperforms PCA. The improvement is largest at close separations to the star (≤4λ/D), providing up to 1.5 mag deeper contrast. This enhancement enables us to detect the exoplanet AF Lep b in data from 2011, 11 yr before its subsequent discovery. We present updated orbital parameters for this object.

Keywords: Astronomy data reduction, Exoplanets, Astronomy image processing, Direct imaging, Interdisciplinary astronomy, High angular resolution
Star Proper Motions Based on Two-epoch Observations from the SDSS and DESI Imaging Surveys. In this study, we present the construction of a new proper-motion catalog utilizing the photometric data from the Sloan Digital Sky Survey (SDSS) and Dark Energy Spectroscopic Instrument (DESI) imaging surveys, with a median time baseline of about 13 yr. To mitigate systematic errors, the DESI galaxy positions are employed to establish a reference frame and to correct the position-, magnitude-, and color-dependent discrepancies between the SDSS and DESI imaging data sets. Spanning 12,589 deg2, the catalog encompasses about 223.7 million non-Gaia objects down to mr ∼ 23. Based on 734,000 quasars, the assessment of the global systematic errors in the DESI‑SDSS proper-motion catalog yields values of 0.06 mas yr‑1 for  and 0.12 mas yr‑1 for μδ. The catalog exhibits precision surpassing 3.4 mas yr‑1, albeit varying with position, color, and magnitude. An additional evaluation employing approximately 2644 distant star samples yields an overall precision of approximately 2.5 and 2.9 mas yr‑1 for  and μδ, respectively. Further comparisons with proper motions from SDSS Stripe 82 reveal a strong consistency between the two data sets. As a practical application, we utilize fainter non-Gaia objects in our catalog to update the proper motions of 15 star clusters. The resulting proper motions for these clusters exhibit excellent consistency with those derived from Gaia data. Our proper-motion measurements, characterized by a deeper limiting magnitude, stand as a valuable complement to the Gaia data set.

Keywords: Astronomy databases, Astrometry, Catalogs, Proper motions
Filling the Gap: The Missing Eclipses of γ Persei from 2005 and from 2006. γ Persei is a long-period (P ≍ 14.6 yr) eclipsing binary system. Its period makes it a difficult target to fully understand: so far, only two primary eclipses are known in the literature, from 1990 and from 2019, whereas the 2005 one was missed due to its closeness to the Sun at the time. We aimed to fill in this gap by processing the quasi-continuous photometry collected by the Solar Mass Ejection Imager (SMEI) between 2003 and 2011, which was ideally positioned to observe such a bright targets. In order to do that, we first determined a color-dependent conversion formula from the SMEI measurements into Gaia G magnitudes. We applied various corrections to the photometry and provide the longest continuous light curve of γ Persei. We successfully detected the 2005 primary eclipse of the system, with the yearly observations ending during the egress of the companion. We predicted the position of a possible secondary eclipse by forward modeling the binary system with PHOEBE, and successfully recovered the secondary eclipse in the 2006 SMEI observations. The existence of the secondary eclipse puts strong constraints on the orbital configuration, which will be an important constraint for future studies of the system.

Keywords: Eclipsing binary stars, Computational methods, Photometry
Orbital and Atmospheric Modeling of H II 1348B: An Eccentric Young Substellar Companion in the Pleiades. Brown dwarfs with known physical properties (e.g., age and mass) are essential for constraining models of the formation and evolution of substellar objects. We present new high-contrast imaging observations of the circumbinary brown dwarf H II 1348B—one of the few known substellar companions in the Pleiades cluster. We observed the system in the infrared   band with the Large Binocular Telescope Interferometer in dual-aperture direct-imaging mode (i.e., with the two telescope apertures used separately) on 2019 September 18. The observations attained a high signal-to-noise ratio (SNR &gt; 150) photometric detection and relative astrometry with uncertainties of ∼5 mas. This work presents the first model of the companion's orbital motion using relative astrometry from five epochs across a total baseline of 23 yr. Orbital fits to the compiled data show the companion's semimajor axis to be   with an eccentricity of  . We infer that H II 1348B has a mass of 60–63 ± 2 MJ from comparison to brown dwarf evolutionary models given the well-constrained distance and age of the Pleiades. No other objects were detected in the H II 1348 system, and through synthetic planet injection and retrievals we establish detection limits at a cluster age of 112 ± 5 Myr down to ∼10–30 MJ for companions with projected separations of 21.5–280 au. With this work, H II 1348B becomes the second directly imaged substellar companion in the Pleiades with measured orbital motion after HD 23514B.

Keywords: Brown dwarfs, Direct imaging, Exoplanets
Further Investigation on Chromospheric Activity Patterns of the RS Canum Venaticorum Star V711 Tauri. We present new long-term spectroscopic observations of the very active RS Canum Venaticorum (RS CVn) star V711 Tauri (V711 Tau), obtained during several observing runs from 2005 to 2021. By means of the spectral-subtraction technique, several optical chromospheric activity indicators Ca II infrared triplet, Hα, Na I D1, D2 doublet, He I D3, and Hβ lines, are analyzed. V711 Tau shows strong excess emission in the chromospheric activity lines, and the emission is mainly associated with the K1 IV primary component. The G5 V secondary component also shows weak emission features. There are four optical flare events during our observations, characterized by the He I D3 line emission features and stronger emission in other activity lines, which have similar order of magnitude as the strong flares of other active RS CVn-type stars. We separate our long-term observations to twelve observing groups, and find that V711 Tau has two active longitudes around phases 0.25 and 0.75 to dominate the activity in most of time. The chromospheric activity level shows a long-term variation, indicating possible chromospheric activity cycle. Moreover, a close spatial connection between photospheric spots and chromospheric active regions in short and long timescale is found for V711 Tau.

Keywords: Stellar chromospheres, Stellar activity, Spectroscopic binary stars, Optical flares, Spectroscopy
Testing Cluster Membership of Planetary Nebulae with High-precision Proper Motions. II. HST Observations of PHR J1315–6555 in the Open Cluster AL 1 (ESO 96-SC04). Planetary nebulae (PNe) shown to be members of star clusters provide information on their properties and evolutionary histories that cannot be determined for PNe in the field, in particular the initial masses of their progenitor stars. Here we investigate the bipolar PN PHR J1315‑6555 (hereafter PHR J1315), which lies near the open cluster AL 1 (ESO 96-SC04) on the sky. Previous work has established that the PN and cluster have similar radial velocities and amounts of interstellar reddening, and similar distances estimated using independent methods. We have obtained new images of the PN and cluster using the Hubble Space Telescope (HST). Combined with archival HST frames taken 12 yr earlier, they provide high-precision proper motions (PMs) for two candidate central stars of PHR J1315. We find that the PMs of both candidates are consistent with those of cluster members, strongly confirming the PN's membership in AL 1. The candidate lying closer to the center of PHR J1315 has the color and luminosity of an early F-type dwarf, suggesting that it may be the optical primary in a close post-common-envelope binary. We used the HST data to construct a color–magnitude diagram for AL 1, which we corrected for significant foreground differential reddening. Isochrone fitting reveals that the cluster lies at a remarkably large distance of about 13 kpc, and has an age of about 1.0 Gyr. The initial mass of the progenitor of PHR J1315 was about 2.1 M⊙. We suggest follow-up investigations that would provide tighter constraints on the object's evolution.

Keywords: Stellar ages, Planetary nebulae nuclei, Planetary nebulae, Proper motions, Space astrometry, Open star clusters
Discovery of a Jupiter Analog Misaligned to the Inner Planetary System in HD 73344. We present the discovery of a Jupiter-like planet, HD 73344 d ( ,   au,  ) based on 27 yr radial velocity (RV) observations from ELODIE, Lick/Hamilton, SOPHIE, APF, and HIRES. HD 73344 also hosts a compact inner planetary system, including a transiting sub-Neptune, HD 73344 b (Pb = 15.61 days,  ), and a nontransiting Saturn-mass planet (Pc = 65.936 days,  ). By analyzing TESS light curves, we identified a stellar rotation period of 9.03 ± 1.3 days. Combining this with   measurements from stellar spectra, we derived a stellar inclination of  . Furthermore, by combining RVs and Hipparcos─Gaia astrometric acceleration, we characterized the three-dimensional orbit of the outer giant planet and constrained its mutual inclination relative to the innermost transiting planet to be 46° &lt; ∆Ibd &lt; 134° (1σ) and 20° &lt; ∆Ibd &lt; 160° (2σ), strongly disfavoring coplanar architectures. Our analytical calculations and N-body simulations reveal that the two inner planets are strongly coupled with each other and undergo nodal precession together around the orbital axis of the giant planet. During nodal precession, the orbital inclinations of inner planets oscillate with time and therefore become misaligned relative to the stellar spin axis. The formation of such systems suggests a history of planet─planet scattering or misalignment between the inner and outer components of protoplanetary disks. The upcoming release of Gaia Data Release 4 will uncover more systems similar to HD 73344, and enable the study of the flatness of exoplanet systems with a mixture of inner and outer planetary systems on a statistical level.

Keywords: Exoplanet dynamics, Space astrometry, Radial velocity, Gaia, Extrasolar gaseous giant planets
Transformer-based Approach for Accurate Asteroid Spectra Taxonomy and Albedo Estimation. China plans to launch a probe (Tianwen-2) around 2025, mainly to explore the near-Earth asteroid 2016 HO3 (469219, Kamo'oalewa). The mission involves close-range exploration, landing, and mining operations that require three-dimensional modeling of the asteroid, which requires prior knowledge of its material composition and uniformity. This information is crucial in progressive or ground exploration processes. Our research focuses on high-precision intelligent inversion of complex physical properties of asteroids based on spectral data, providing support for further analysis of asteroid materials, density, and structure. We have developed a platform for asteroid spectral classification, albedo estimation, and composition analysis, which includes three types of neural networks based on the Transformer attention mechanism: one for spectral classification, achieving a four-class classification accuracy of 94.58% and an 11-class classification accuracy of 95.69%, a second one for albedo estimation, with an average absolute error of 0.0308 in S-type asteroid albedo estimation, and the third one for composition analysis, with a predicted spectral angular distance of only 0.0340 and an rms error of 0.1759 for the abundance of endmembers. These results indicate that our network can provide high-precision asteroid spectral classification, albedo estimation, and composition analysis results. In addition, we utilized the platform to analyze and provide results for six asteroids.

Keywords: Main belt asteroids, Asteroids, Spectroscopy
Detection of Semidetached Eclipsing Binaries from TESS. Semidetached binaries, distinguished by their mass transfer phase, play a crucial role in elucidating the physics of mass transfer within interacting binary systems. To identify these systems in eclipsing binary light curves provided by large-scale time-domain surveys, we have developed a methodology by training two distinct models that establish a mapping relationship between the parameters (orbital parameters and physical parameters) of semidetached binaries and their corresponding light curves. The first model corresponds to scenarios where the more massive star fills its Roche lobe, while the second model addresses situations where the less massive star does so. In consideration of the O'Connell effect observed in the light curves, we integrated a cool spot parameter into our models, thereby enhancing their applicability to fit light curves that exhibit this phenomenon. Our two-model framework was then harmonized with the Markov Chain Monte Carlo algorithm, enabling precise and efficient light-curve fitting and parameter estimation. Leveraging 2 minute cadence data from the initial 67 sectors of the Transiting Exoplanet Survey Satellite, we successfully identified 327 systems where the less massive component fills its Roche lobe, alongside three systems where the more massive component fills its Roche lobe. Additionally, we offer comprehensive fundamental parameters for these binary systems, including orbital inclination, relative radius, mass ratio, and effective temperature.

Keywords: Eclipsing binary stars, Binary stars, Semi-detached binary stars
Mapping the Filamentary Nebula of NGC 1275 with Multiwavelength SITELLE Observations. The filamentary nebula encompassing the central galaxy of the Perseus Cluster, NGC 1275, is a complex structure extending dozens of kiloparsecs from NGC 1275. Decades of previous works have focused on establishing the primary formation and ionization mechanisms in different filaments. These studies have pointed to a lack of star formation in the majority of the filaments, the importance of magnetic fields and turbulence in several regions, and the role of interactions between the intracluster medium (ICM) and the cool gas in the filaments, as well as the role of interaction between the central radio source, 3C84, and the filaments. In this paper, we present multi-filter observations of the entire filamentary system that cover the optical bandpass, using the SITELLE instrument at the Canada-France-Hawai'i Telescope. Here, we use the data analysis software, LUCI (https://crhea93.github.io/LUCI/index.html), to produce flux maps of the prominent emission lines present in the filters: [O II]λ3726/3729, [O III]λ5007, Hβ, [N II]λ6548, [N II]λ6583, and Hα. We use these maps to produce Baldwin–Phillips–Terlevich and WHAN diagrams to study the ionization mechanisms at play in each distinct region of the filamentary nebula. First, we confirm the absence of [O III]λ5007 in the extended filaments, although we detect this line in the central core, revealing a compact region where photoionization by the active galactic nucleus might affect local conditions. Our findings corroborate previous claims that the ionization in the extended filaments could be caused by the cooling ICM via collisional excitation and/or mixing. Moreover, they support the conclusion that magnetic fields play an important role in the formation and continued existence of the filaments.

Keywords: Galaxy spectroscopy, Galaxies, Galactic and extragalactic astronomy
Constraining Atmospheric Composition from the Outflow: Helium Observations Reveal the Fundamental Properties of Two Planets Straddling the Radius Gap. TOI-836 is a ∼2–3 Gyr K dwarf with an inner super Earth (R = 1.7 R⊕, P = 3.8 days) and an outer mini-Neptune (R = 2.6 R⊕, P = 8.6 days). JWST/NIRSpec 2.8–5.2 μm transmission spectra are flat for both planets. We present Keck/NIRSPEC observations of escaping helium for super-Earth b, which shows no excess absorption in the 1083 nm triplet to deep limits (&lt;0.2%), and mini-Neptune c, which shows strong (0.7%) excess absorption in both visits. These results demonstrate that planet c retains at least some primordial atmosphere, while planet b is consistent with having lost its entire primordial envelope. Self-consistent 1D radiative-hydrodynamic models of planet c reveal that the helium excess absorption signal is highly sensitive to metallicity: its equivalent width collapses by a factor of 13 as metallicity increases from 10 times to 100 times solar, and by a further factor of 12 as it increases to 200 times solar. The observed equivalent width is 88% of the model prediction for 100 times metallicity, suggesting an atmospheric metallicity similar to K2-18b and TOI-270d, the first two mini-Neptunes with detected absorption features in JWST transmission spectra. We highlight the helium triplet as a potentially powerful probe of atmospheric composition, with complementary strengths and weaknesses to atmospheric retrievals. The main strength is its extreme sensitivity to metallicity in the scientifically significant range of 10–200 times solar, and the main weakness is the enormous model uncertainties in outflow suppression and confinement mechanisms, such as magnetic fields and stellar winds, which can suppress the signal by at least a factor of ∼several.

Keywords: Exoplanet evolution, Exoplanet atmospheric composition , Exoplanet atmospheres, Exoplanet atmospheric evolution
Identification of Megaconstellations in Wide-field Astronomical Images with Machine Learning. Along with the development of megaconstellation, tens of thousands of artificial satellites are going to be launched and deployed, it poses a serious space sustainability risk and has a serious impact on astronomical observations. For wide-field optical astronomical surveys, the large number of satellites increases the probability that one will enter the field of view and streak-like image with distinct brightness and large size appears, data reduction efficiency is affected and image measurement pipeline may be interrupted. Automatic identification of the appearance of megaconstellation images in survey data can make contributions to optimize the data reduction pipeline and propose new mitigation standards and guidelines. Here an automatic identification pipeline based on machine learning model ShuffleNet V2 is developed, after trained with large amount of raw data, high efficiency is achieved. A trial survey was performed using an optical telescope with 4.8 square degrees field and raw images of 77 nights were obtained. With SExtractor and manual identification, the streak images of low-Earth orbital satellites are selected, and the efficiency of our method is investigated. It is demonstrated that an accuracy rate better than 98% and a recall rate better than 95% are achieved by our framework, and can be aware of the images with satellite signals effectively. Our method presented can be used as an auxiliary tool for reduction pipeline optimization and improving source measurements, and it deserves wide applications in similar tasks.

Keywords: Observational astronomy, Artificial satellites, Ground-based astronomy, Neural networks
Anomaly Detection and Radio-frequency Interference Classification with Unsupervised Learning in Narrowband Radio Technosignature Searches. The search for radio technosignatures is an anomaly detection problem: Candidate signals represent needles of interest in the proverbial haystack of radio-frequency interference (RFI). Current search frameworks find an enormity of false-positive signals, especially in large surveys, requiring manual follow-up to a sometimes prohibitive degree. Unsupervised learning provides an algorithmic way to winnow the most anomalous signals from the chaff, as well as group together RFI signals that bear morphological similarities. We present Grouping Low-frequency Observations By Unsupervised Learning After Reduction (GLOBULAR) clustering, a signal processing method that uses hierarchical density-based spatial clustering of applications with noise (or HDBSCAN) to reduce the false-positive rate and isolate outlier signals for further analysis. When combined with a standard narrowband signal detection and spatial filtering pipeline, such as turboSETI, GLOBULAR clustering offers significant improvements in the false-positive rate over the standard pipeline alone, suggesting dramatic potential for the amelioration of manual follow-up requirements for future large surveys. By removing RFI signals in regions of high spectral occupancy, GLOBULAR clustering may also enable the detection of signals missed by the standard pipeline. We benchmark our method against the C. Choza et al. turboSETI-only search of 97 nearby galaxies at the L band, demonstrating a false-positive hit reduction rate of 93.1% and a false-positive event reduction rate of 99.3%.

Keywords: Technosignatures, Outlier detection, Clustering, Search for extraterrestrial intelligence, Radio astronomy