Sazuna/UAT_keywords huggingface dataset:
Prospects from TESS and Gaia to Constrain the Flatness of Planetary Systems. The mutual inclination between planets orbiting the same star provides key information to understand the formation and evolution of multiplanet systems. In this work, we investigate the potential of Gaia astrometry in detecting and characterizing cold Jupiters in orbits exterior to the currently known Transiting Exoplanet Survey Satellite (TESS) planet candidates. According to our simulations, out of the ~3350 systems expected to have cold Jupiter companions, Gaia, by its nominal 5 yr mission, should be able to detect ~200 cold Jupiters and measure the orbital inclinations with a precision of ${\sigma }_{\cos i}\lt 0.2$ in ~120 of them. These numbers are estimated under the assumption that the orbital orientations of the CJs follow an isotropic distribution, but these only vary slightly for less broad distributions. We also discuss the prospects from radial velocity follow-ups to better constrain the derived properties and provide a package to do quick forecasts using our Fisher matrix analysis. Overall, our simulations show that Gaia astrometry of cold Jupiters orbiting stars with TESS planets can distinguish dynamically cold (mean mutual inclination ≲5°) from dynamically hot systems (mean mutual inclination ≳20°), placing a new set of constraints on their formation and evolution.

Keywords: Exoplanet migration, Exoplanet catalogs, Exoplanets, Extrasolar gaseous planets, Space astrometry
Validating AU Microscopii d with Transit Timing Variations. AU Mic is a young (22 Myr), nearby exoplanetary system that exhibits excess transit timing variations (TTVs) that cannot be accounted for by the two known transiting planets nor stellar activity. We present the statistical "validation" of the tentative planet AU Mic d (even though there are examples of "confirmed" planets with ambiguous orbital periods). We add 18 new transits and nine midpoint times in an updated TTV analysis to prior work. We perform the joint modeling of transit light curves using EXOFASTv2 and extract the transit midpoint times. Next, we construct an O-C diagram and use Exo-Striker to model the TTVs. We generate TTV log-likelihood periodograms to explore possible solutions for d's period, then follow those up with detailed TTV and radial velocity Markov Chain Monte Carlo modeling and stability tests. We find several candidate periods for AU Mic d, all of which are near resonances with AU Mic b and c of varying order. Based on our model comparisons, the most-favored orbital period of AU Mic d is 12.73596 ± 0.00793 days (T  C,d = 2458340.55781 ± 0.11641 BJD), which puts the three planets near 4:6:9 mean-motion resonance. The mass for d is 1.053 ± 0.511 M ⊕, making this planet Earth-like in mass. If confirmed, AU Mic d would be the first known Earth-mass planet orbiting a young star and would provide a valuable opportunity in probing a young terrestrial planet's atmosphere. Additional TTV observations of the AU Mic system are needed to further constrain the planetary masses, search for possible transits of AU Mic d, and detect possible additional planets beyond AU Mic c.

Keywords: Exoplanet astronomy, Exoplanet systems, Exoplanets, Exoplanet dynamics
The Return of the Rosetta Target: Keck Near-infrared Observations of Comet 67P/Churyumov-Gerasimenko in 2021. High-resolution near-infrared ground-based spectroscopic observations of comet 67P/Churyumov-Gerasimenko near its maximum activity in 2021 were conducted from the W. M. Keck Observatory, using the facility spectrograph NIRSPEC. 67P is the best-studied comet to date because of the unprecedented detail and insights provided by the Rosetta mission during 2014-2016. Because 67P is the only comet where the detailed abundances of many coma volatiles were measured in situ, determining its composition from the ground provides a unique opportunity to interpret Rosetta results within the context of the large database of ground-based compositional measurements of comets. However, previous apparitions, including in 2015, have been unfavorable for in-depth ground-based studies of parent volatiles in 67P. The 2021 apparition of 67P was thus the first-ever opportunity for such observations. We report gas spatial distributions, rotational temperatures, production rates, and relative abundances (or stringent upper limits) among seven volatile species: C2H2, C2H6, HCN, NH3, CH3OH, H2CO, and H2O. The measured abundances of trace species relative to water reveal near average or below average values compared to previous comets studied at infrared wavelengths. Both gas rotational temperatures and the spatial distributions of H2O, C2H6, and HCN measured with Keck-NIRSPEC in 2021 are consistent with the outgassing patterns revealed by Rosetta in 2015 at very similar heliocentric distance (post-perihelion). These results can be integrated with both Rosetta mission findings and ground-based cometary studies of the overall comet population, for which we encourage a wide-scale collaboration across measurement techniques.

Keywords: Small Solar System bodies, Comae, Short period comets, Solar system, Neutral coma gases, Comets
No Evidence for More Earth-sized Planets in the Habitable Zone of Kepler's M versus FGK Stars. Reliable detections of Earth-sized planets in the habitable zone remain elusive in the Kepler sample, even for M dwarfs. The Kepler sample was once thought to contain a considerable number of M-dwarf stars (T eff &lt; 4000 K), which hosted enough Earth-sized ([0.5, 1.5] R ⊕) planets to estimate their occurrence rate (η ⊕) in the habitable zone. However, updated stellar properties from Gaia have shifted many Kepler stars to earlier spectral type classifications, with most stars (and their planets) now measured to be larger and hotter than previously believed. Today, only one partially reliable Earth-sized candidate remains in the optimistic habitable zone, and zero in the conservative zone. Here we performed a new investigation of Kepler's Earth-sized planets orbiting M-dwarf stars, using occurrence rate models with considerations of updated parameters and candidate reliability. Extrapolating our models to low instellations, we found an occurrence rate of ${\eta }_{\oplus }={8.58}_{-8.22}^{+17.94} \% $ for the conservative habitable zone (and ${14.22}_{-12.71}^{+24.96} \% $ for the optimistic one), consistent with previous works when considering the large uncertainties. Comparing these estimates to those from similarly comprehensive studies of Sun-like stars, we found that the current Kepler sample does not offer evidence to support an increase in η ⊕ from FGK to M stars. While the Kepler sample is too sparse to resolve an occurrence trend between early and mid- to late M dwarfs for Earth-sized planets, studies including larger planets and/or data from the K2 and TESS missions are well suited to this task.

Keywords: Habitable zone, Exoplanets
PNet-A Deep Learning Based Photometry and Astrometry Bayesian Framework. Time-domain astronomy has emerged as a vibrant research field in recent years, focusing on celestial objects that exhibit variable magnitudes or positions. Given the urgency of conducting follow-up observations for such objects, the development of an algorithm capable of detecting them and determining their magnitudes and positions has become imperative. Leveraging the advancements in deep neural networks, we present PNet, an end-to-end framework designed not only to detect celestial objects and extract their magnitudes and positions, but also to estimate the photometric uncertainty. PNet comprises two essential steps. First, it detects stars and retrieves their positions, magnitudes, and calibrated magnitudes. Subsequently, in the second phase, PNet estimates the uncertainty associated with the photometry results, serving as a valuable reference for the light-curve classification algorithm. Our algorithm has been tested using both simulated and real observation data, demonstrating the ability of PNet to deliver consistent and reliable outcomes. Integration of PNet into data-processing pipelines for time-domain astronomy holds significant potential for enhancing response speed and improving the detection capabilities for celestial objects with variable positions and magnitudes.

Keywords: CCD photometry, Bayesian statistics, Neural networks, Time domain astronomy, Photographic astrometry
Empirical 2MASS-WFC3/IR Filter Transformations Across the H-R Diagram from Synthetic Photometry. Near-infrared bandpasses on spaceborne observatories diverge from their ground-based counterparts as they are free of atmospheric telluric absorption. Available transformations between respective filter systems in the literature rely on theoretical stellar atmospheres, which are known to have difficulties reproducing the observed spectral energy distributions of cool giants. We present new transformations between the Two Micron All Sky Survey JHK  S  and Hubble Space Telescope WFC3/IR F110W, F125W, and F160W photometric systems based on synthetic photometry of empirical stellar spectra from four spectral libraries. This sample comprises over 1000 individual stars, which together span nearly the full H-R diagram and sample stellar populations from the solar neighborhood out to the Magellanic Clouds, covering a broad range of ages, metallicities, and other relevant stellar properties. In addition to global color-dependent transformations, we examine band-to-band differences for cool, luminous giant stars in particular, including multiple types of primary distance indicators.

Keywords: Photometric systems, Stellar populations, Infrared astronomy, Calibration, Stellar colors
Characterization and Absolute Calibration of the Far-infrared Field Integral Line Spectrometer for SOFIA. We present the characterization and definitive flux calibration of the Far-infrared Field Integral Line Spectrometer (FIFI-LS) instrument on board SOFIA. The work is based on measurements made in the laboratory with an internal calibrator and on observations of planets, moons, and asteroids as absolute flux calibrators made during the entire lifetime of the instrument. We describe the techniques used to derive flat fields, water vapor column estimates, detector linearity, spectral and spatial resolutions, and absolute flux calibration. Two sets of responses are presented, before and after the entrance filter window was changed in 2018 to improve the sensitivity at 52 μm, a wavelength range previously not covered by PACS on Herschel. The relative spectral response of each detector and the illumination pattern of the arrays of the FIFI-LS arrays are derived using the internal calibrator before each observational series. The linearity of the array response is estimated by considering observations of bright sources. We find that the deviation from the linearity of the FIFI-LS arrays affects the flux estimations by less than 1%. The flux calibration accuracy is estimated to be 15% or better across the entire wavelength range of the instrument. The limited availability of sky calibrators during each observational series is the major limiting factor of the flux calibration accuracy.

Keywords: Astronomical instrumentation, Flux calibration, Far infrared astronomy
Compositional Constraints of Ice Lobes at the Edge of Martian South Polar Cap and the Possibility for CO<SUB>2</SUB> Ice. As one of the major ice reservoirs on Mars, the south polar layered deposits (SPLD) are mainly composed of water ice and dust except for the perennial CO2 ice deposits on the surface and within buried layers. At the edge of Planum Australe, the Shallow Radar detected the base of two ice lobes, which can be used to estimate their dielectric properties and analyze the components. These measurements, combined with topographic data, allow for the relative permittivity of the lobe materials to be estimated at 2.73 ± 0.67. Under the constraint of the SPLD density, the permittivity value translates to the existence of CO2 ice depending on the dust content. If the dust content is larger than 24%, the lobes are CO2 free and composed of water ice, dust, and pore space. Whereas, for the dust content of &lt;12%, our results suggest that the lobes must contain a certain amount of CO2 ice, which could be an average volume of 30%. When the dust content is between 12% and 24%, the existence of CO2 ice is undetermined. This study improves the understanding of ice deposits at the Martian south polar.

Keywords: Mars, Martian satellites, Radar astronomy, Computational methods
Giant Outer Transiting Exoplanet Mass (GOT 'EM) Survey. III. Recovery and Confirmation of a Temperate, Mildly Eccentric, Single-transit Jupiter Orbiting TOI-2010. Large-scale exoplanet surveys like the Transiting Exoplanet Survey Satellite (TESS) mission are powerful tools for discovering large numbers of exoplanet candidates. Single-transit events are commonplace within the resulting candidate list due to the unavoidable limitation of the observing baseline. These single-transit planets often remain unverified due to their unknown orbital periods and consequent difficulty in scheduling follow-up observations. In some cases, radial velocity (RV) follow up can constrain the period enough to enable a future targeted transit detection. We present the confirmation of one such planet: TOI-2010 b. Nearly three years of RV coverage determined the period to a level where a broad window search could be undertaken with the Near-Earth Object Surveillance Satellite, detecting an additional transit. An additional detection in a much later TESS sector solidified our final parameter estimation. We find TOI-2010 b to be a Jovian planet (M  P  = 1.29 M Jup, R  P  = 1.05 R Jup) on a mildly eccentric orbit (e = 0.21) with a period of P = 141.83403 days. Assuming a simple model with no albedo and perfect heat redistribution, the equilibrium temperature ranges from about 360 to 450 K from apastron to periastron. Its wide orbit and bright host star (V = 9.85) make TOI-2010 b a valuable test bed for future low-insolation atmospheric analysis.

Keywords: Exoplanet astronomy, Exoplanet detection methods, Exoplanet systems, Exoplanet dynamics
SOFIA FEEDBACK Survey: The Pillars of Creation in [C II] and Molecular Lines. We investigate the physical structure and conditions of photodissociation regions (PDRs) and molecular gas within the Pillars of Creation in the Eagle Nebula using SOFIA FEEDBACK observations of the [C II] 158 μm line. These observations are velocity resolved to 0.5 km s-1 and are analyzed alongside a collection of complimentary data with similar spatial and spectral resolution: the [O I] 63 μm line, also observed with SOFIA, and rotational lines of CO, HCN, HCO+, CS, and N2H+. Using the superb spectral resolution of SOFIA, APEX, CARMA, and BIMA, we reveal the relationships between the warm PDR and cool molecular gas layers in context of the Pillars' kinematic structure. We assemble a geometric picture of the Pillars and their surroundings informed by illumination patterns and kinematic relationships and derive physical conditions in the PDRs associated with the Pillars. We estimate an average molecular gas density ${n}_{{{\rm{H}}}_{2}}\sim 1.3\,\times \,{10}^{5}$ cm-3 and an average atomic gas density n H ~ 1.8 × 104 cm-3 and infer that the ionized, atomic, and molecular phases are in pressure equilibrium if the atomic gas is magnetically supported. We find pillar masses of 103, 78, 103, and 18 M ☉ for P1a, P1b, P2, and P3, respectively, and evaporation times of ~1-2 Myr. The dense clumps at the tops of the pillars are currently supported by the magnetic field. Our analysis suggests that ambipolar diffusion is rapid and these clumps are likely to collapse within their photoevaporation timescales.

Keywords: Interstellar clouds, Stellar feedback, Photodissociation regions
The Galactic Interstellar Object Population: A Framework for Prediction and Inference. The Milky Way is thought to host a huge population of interstellar objects (ISOs), numbering approximately 1015 pc-3 around the Sun, which are formed and shaped by a diverse set of processes ranging from planet formation to Galactic dynamics. We define a novel framework, first to predict the properties of this Galactic ISO population by combining models of processes across planetary and Galactic scales, and second to make inferences about the processes being modeled, by comparing the predicted population to what is observed. We predict the spatial and compositional distribution of the Galaxy's population of ISOs by modeling the Galactic stellar population with data from the APOGEE survey and combining this with a protoplanetary disk chemistry model. Selecting the ISO water mass fraction as an example observable quantity, we evaluate its distribution both at the position of the Sun and averaged over the Galactic disk; our prediction for the solar neighborhood is compatible with the inferred water mass fraction of 2I/Borisov. We show that the well-studied Galactic stellar metallicity gradient has a corresponding ISO compositional gradient. We also demonstrate the inference part of the framework by using the current observed ISO composition distribution to constrain the parent star metallicity dependence of the ISO production rate. This constraint, and other inferences made with this framework, will improve dramatically as the Vera C. Rubin Observatory Legacy Survey of Space and Time progresses and more ISOs are observed. Finally, we explore generalizations of this framework to other Galactic populations, such as that of exoplanets.

Keywords: Small Solar System bodies, Milky Way evolution, Interstellar objects
CHIMERA Occultation Constraints on the Abundance of Kilometer-scale Kuiper Belt Objects. Occultations provide indirect sensitivity to the number density of small Kuiper Belt objects (KBOs) too faint to directly detect telescopically. We present results from the Caltech HI-speed Multicolor camERA (CHIMERA) survey with the Palomar Hale Telescope, which monitored stars over the central $5^{\prime} \times 5^{\prime} $ of the M22 globular cluster along the ecliptic plane for serendipitous occultations by kilometer-scale KBOs over 63 hr across 24 nights at a 33 Hz frame rate simultaneously in $i^{\prime} $ and $g^{\prime} $ . We adapted dense-field photometry and occultation template fitting techniques to this data set, finding a 95% confidence upper limit on the occultation rate, corresponding to an ecliptic sky density of ≲107 deg-2 of &gt;1 km diameter classical KBOs. We discuss a few of the occultation-like light curve signatures at the edge of the sensitivity limit responsible for setting the upper bounds, and their likely nonviability as true occultations.

Keywords: Stellar occultation, Multi-color photometry, Kuiper belt
Planets Across Space and Time (PAST). IV. The Occurrence and Architecture of Kepler Planetary Systems as a Function of Kinematic Age Revealed by the LAMOST-Gaia-Kepler Sample. One of the fundamental questions in astronomy is how planetary systems form and evolve. Measuring the planetary occurrence and architecture as a function of time directly addresses this question. In the fourth paper of the Planets Across Space and Time series, we investigate the occurrence and architecture of Kepler planetary systems as a function of kinematic age by using the LAMOST-Gaia-Kepler sample. To isolate the age effect, other stellar properties (e.g., metallicity) have been controlled. We find the following results. (1) The fraction of stars with Kepler-like planets (F Kep) is about 50% for all stars; no significant trend is found between F Kep and age. (2) The average planet multiplicity ( ${\bar{N}}_{p}$ ) exhibits a decreasing trend (~2σ significance) with age. It decreases from ${\bar{N}}_{p}$ ~ 3 for stars younger than 1 Gyr to ${\bar{N}}_{p}$ ~ 1.8 for stars of about 8 Gyr. (3) The number of planets per star (η = F Kep× ${\bar{N}}_{p}$ ) also shows a decreasing trend (~2σ-3σ significance). It decreases from η ~ 1.6-1.7 for young stars to η ~ 1.0 for old stars. (4) The mutual orbital inclination of the planets (σ  i,k ) increases from $1\buildrel{\circ}\over{.} {2}_{-0.5}^{+1.4}$ to $3\buildrel{\circ}\over{.} {5}_{-2.3}^{+8.1}$ as the stars age from 0.5 to 8 Gyr with a best fit of $\mathrm{log}{\sigma }_{i,k}=0.2+0.4\times \mathrm{log}\tfrac{\mathrm{Age}}{1\mathrm{Gyr}}$ . Interestingly, the solar system also fits such a trend. The fact that F Kep remains relatively constant at approximately ~ 50% across different ages suggests the robustness of planet formation throughout the history of the Galaxy. The age dependence of ${\bar{N}}_{p}$ and σ  i,k  demonstrates that the planetary architecture is evolving, and planetary systems generally become dynamically hotter with fewer planets as they age.

Keywords: Planetary system evolution, Exoplanets
Red Giants Search Method Based on Convolutional Neural Networks. Red giants play a crucial role in astronomical exploration. However, the current search for these stars heavily relies on spectrum analysis, making it a cumbersome process. In this paper, we propose a novel red giant search approach called CBAMResNets. CBAMResNets enhances feature extraction from images by incorporating the Convolutional Block Attention Module into the ResNets model. To train and validate our model, we utilize accurately labeled stellar image data obtained by combining the Sky Mapper Southern Survey (SMSS) and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. Our experiments demonstrate that CBAMResNets outperforms other networks such as VGG16 and TPC across most performance metrics and remains competitive with traditional machine-learning methods. Specifically, for stars within the magnitude range of 11-19 in the u band, our model achieves a precision rate of 0.92 and a recall rate of 0.9194. Similarly, for stars within the magnitude range of 11-15 in the u band, the precision rate is 0.92, and the recall rate is 0.9813. Furthermore, we apply CBAMResNets to the SMSS subregion, resulting in the identification of 20,243 potential red giant candidates out of the 304,477 observed stars. We validate the authenticity of these candidates by analyzing their stellar absolute magnitudes and temperatures, estimating a contamination rate of approximately 6.4%. Additionally, we examine the approximate distribution of their metallicity. The catalog containing the identified red giant candidates can be accessed at Zenodo. 4 4 doi:10.5281/zenodo.8352420

Keywords: Stellar photometry, Convolutional neural networks, Fundamental parameters of stars, Red giant stars
A Solution to Continuous RFI in Narrowband Radio SETI with FAST: The MultiBeam Point-source Scanning Strategy. Narrowband radio search for extraterrestrial intelligence (SETI) in the 21st century suffers severely from radio frequency interference (RFI), resulting in a high number of false positives, and it could be the major reason why we have not yet received any messages from space. We thereby propose a novel observation strategy, called MultiBeam Point-source Scanning (MBPS), to revolutionize the way RFI is identified in narrowband radio SETI and provide a prominent solution to the current situation. The MBPS strategy is a simple yet powerful method that sequentially scans over the target star with different beams of a telescope, creating real-time references in the time domain for cross-verification and thus potentially identifying all continuous RFI with a level of certainty never achieved in any previous attempts. By applying the MBPS strategy during the observation of TRAPPIST-1 with the Five-hundred-meter Aperture Spherical radio Telescope, we successfully identified all 6972 received signals as RFI using the solid criteria introduced by the MBPS strategy. Therefore, we present the MBPS strategy as a promising tool that should bring us much closer to the first discovery of a genuine galactic greeting.

Keywords: Search for extraterrestrial intelligence, Radio telescopes, Astronomical instrumentation