Sazuna/UAT_keywords huggingface dataset:
What if it Rains on Your Eclipse: Planning Ahead for August 2045. It was a dark and drizzly afternoon, not far out of San Antonio, TX—at least for those of us who had chosen to take up watch in D'Hanis; others were more fortuitously situated in, for instance, Greenville—when we saw the 2024 April 8 total solar eclipse over the continental USA. For most, a total solar eclipse is a once-in-a-lifetime phenomenon, often enveloped in myth and wonder. Some US citizens having enjoyed two spectacular events in just under 7 years are jaded while others are speculating on the possibilities of visiting foreign lands or waiting to explore Alaska in 2033 March. The next total solar eclipse to sweep all the way across the contiguous US will be 2045 August 12. Then, a narrow path across the United States will experience up to 6 minutes and 6 seconds of totality. Based on public outreach efforts surrounding the 2017 August and 2024 April events, the 2025 eclipse will present a remarkable opportunity for public engagement with a new generation located within the eclipse corridor. However, the question remains: what if it rains? If unable to relocate to cloud-free skies, tracking changes in irradiance and temperature throughout the partial and total phases of the eclipse is still possible. In 2017 and 2024, we measured solar illuminance, temperature, humidity, and pressure during the solar eclipses and other reference times with Raspberry Pi-based systems, which we present for consideration by others preparing for future opportunities. Under clear skies, observational projects like these can complement your sensory experience. Although 2045 may seem distant to most, careful planning and creative problem-solving will ensure a successful and engaging outreach program, regardless of weather conditions. We also evaluate the changing illuminance throughout the solar eclipses as surrogates for changing conditions during twilight periods. The natural light available when the Sun is near, but below, the horizon is more complicated than the traditional divisions of civil, nautical, and astronomical twilights. We consider the feasibility of using similar detectors to collect data from which we could produce more nuanced illuminance models for use in the polar regions where the Sun may linger near the horizon for hours.

Keywords: Solar spectral irradiance, Solar eclipses, Astronomical instrumentation, Solar instruments
Beyond Astronomy Content: Communications Skills for All Our Students (a dangerous idea). Effective science communication is essential for disseminating astronomy research. Furthermore, communications skills are essential to preparing all our students for their future careers, regardless of field. Equally important, by explaining what she or he is learning, a student solidifies his or her learning and reveals areas of weakness, enabling further improvement. In addition, bringing language skills to astronomy classrooms demonstrates the interconnectedness of knowledge and increases the interdisciplinary nature of our curricula. As part of the 2024 "New Technologies and Dangerous Questions in Astronomy Education" workshop at the University of North Carolina, Chapel Hill, the authors advocated for the integration of communication and writing skills in astronomy education at all levels. We argue that teaching students how to communicate their ideas effectively, whether through writing or speaking assignments, fosters deeper understanding of astronomy content and enhances career readiness across all professions. To that end, we explore strategies for incorporating communication exercises into astronomy courses with intentionality but without overburdening instructors. Opportunities for student communication assignments include formal and informal writing assignments, problem sets, laboratory reports, and special topic presentations, such as many instructors already include in their syllabi. Instructors can tailor the format and depth of any of these to either majors and non-majors. They can also adopt assessment strategies that encourage students to improve continuously while providing consistent and clear expectations. Fortunately, instructors can rely on an ecosystem of student supports, such as campus writing and speaking centers, to craft appropriate assignments. Overall, we encourage instructors to pay as much attention to the science communication opportunities in their classroom as they do to crafting engaging astronomy content.

Keywords: Astronomy education
The NEID Earth Twin Survey. I. Confirmation of a 31 Day Planet Orbiting HD 86728. With close to 3 yr of observations in hand, the NEID Earth Twin Survey (NETS) is starting to unearth new astrophysical signals for a curated sample of bright, radial velocity (RV)-quiet stars. We present the discovery of the first NETS exoplanet, HD 86728b, a   planet on a circular,   day orbit, thereby confirming a candidate signal identified by L. A. Hirsch et al. We confirm the planetary origin of the detected signal, which has a semi-amplitude of just   m s‑1, via careful analysis of the NEID RVs and spectral activity indicators, and we constrain the mass and orbit via fits to NEID and archival RV measurements. The host star is intrinsically quiet at the ∼1 m s‑1 level, with the majority of this variability likely stemming from short-timescale granulation. HD 86728b is among the small fraction of exoplanets with similar masses and periods that have no known planetary siblings.

Keywords: Surveys, Radial velocity, Exoplanet detection methods, Exoplanets
Unfolding X-Ray Spectral Data: Conditions and Applications. We present conditions for which X-ray spectra can be "unfolded" to present an accurate representation of the true source spectra. The method we use to unfold the data is implemented in the Interactive Spectral Interpretation Software and distinguishes itself as being model-independent. We find that this method of unfolding makes accurate representations of the true source spectra: (1) The detector is high-resolution, and (2) The spectrum is not steeply sloped. These criteria are not simple conditions that give concrete determinations; each detector and spectrum must be judged individually. We find that both grating and imaging detectors can be unfolded with minimal distortions as compared to both continuum and local spectral features, the latter CCD detectors being much more energy dependent. We also provide example use cases for unfolding in the context of current generation X-ray observatories and important caveats.

Keywords: X-ray astronomy, CCD observation, Astronomy data reduction, Spectroscopy
Finite-lens Effect on Self-lensing in Detached White Dwarfs-main Sequence Binary Systems. In edge-on and detached binary systems, including a white dwarf (WD) and a main-sequence (MS) star system (or WDMS), when the source star is passing behind the compact companion its light is bent and magnified. Meanwhile, some part of its image's area is obscured by the WD's disk. These two effects occur simultaneously, and the observer receives the stellar light magnified and partially obscured due to the finite lens size. We study these effects in different WDMS binary systems numerically using inverse ray-shooting and analytically using approximate relations close to reality. For WDMS systems with long orbital periods ≳300 days and M WD ≳ 0.2M ☉ (where M WD is the mass of the WD), lensing effects dominate the occultations due to finite-lens effects, and for massive WDs with masses higher than solar mass, no occultation happens. The occultations dominate self-lensing signals in systems with low-mass WDs (M WD ≲ 0.2M ☉) in close orbits with short orbital periods T ≲ 50 days. The occultation and self-lensing cancel each other out when the WD's radius equals   times the Einstein radius, regardless of the source radius, which offers a decreasing relation between the orbital period and WD mass. We evaluate the errors in the maximum deviation in the self-lensing/occultation normalized flux, which is done by using its known analytical relation, and conclude that these errors could be up to 0.002, 0.08, and 0.03 when the orbital period is T = 30, 100, and 300 days, respectively. The size of stellar companions in WDMS systems has a twofold manner, decreasing the depth of self-lensing/occultation signals but enlarging their width.

Keywords: White dwarf stars, Compact binary stars, Computational methods, Gravitational lensing, Occultation, Eclipsing binary stars, Astronomical simulations
Origins of Super Jupiters: TOI-2145b has a Moderately Eccentric and Nearly Aligned Orbit. Super Jupiters are giant planets with several Jupiter masses. It remains an open question whether these planets originate with such high masses or grow through collisions. Previous work demonstrates that warm super Jupiters tend to have more eccentric orbits compared to regular-mass warm Jupiters. This correlation between mass and eccentricity may indicate that planet–planet interactions significantly influence the warm giant planet demographics. Here, we conducted a detailed characterization of a warm super Jupiter, TOI-2145b. This analysis utilized previous observations from Transiting Exoplanet Survey Satellite and Keck/High Resolution Echelle Spectrometer, enhanced by new Rossiter–McLaughlin effect data from the NEID spectrometer on the 3.5 m WIYN Telescope. TOI-2145b is a   M Jup planet on a moderate eccentricity (e =  ), 10.26 day orbit, orbiting an evolved A-star. We constrain the projected stellar obliquity to be λ =  ° from two NEID observations. Our N-body simulations suggest that the formation of super Jupiter TOI-2145b could involve either of two scenarios: a high initial mass or growth via collisions. On a population level, however, the collision scenario can better describe the mass–eccentricity distribution of observed warm Jupiters.

Keywords: Exoplanet formation, Transits, Exoplanets
Long-term Dynamical Stability in the Outer Solar System. II. Detailed Secular Evolution of Four Large Regular and Resonant Trans-Neptunian Objects. The long-term evolution of the outer solar system is subject to the influence of the giant planets, however, perturbations from other massive bodies located in the region imprint secular signatures, which are discernible in long-term simulations. In this work, we performed an in-depth analysis of the evolution of massive objects Eris, 2015 KH162, Pluto, and 2010 EK139 (aka, Dziewanna), subject to perturbations from the giant planets and the 34 largest trans-Neptunian objects. We do this by analyzing 200, 1 Gyr long simulations with identical initial conditions, but requiring the numerical integrator to take different time steps for each realization. Despite the integrator's robustness, each run's results are surprisingly different, showing the limitations of individual realizations when studying the trans-Neptunian region due to its intrinsic chaotic nature. For each object, we find orbital variables with well-defined oscillations and limits, and others with surprisingly large variances and seemingly erratic behaviors. We found that 2015 KH162 is a nonresonant and very stable object that experiences only limited orbital excursions. Pluto is even more stable and we found a new underlying constraining mechanism for its orbit; 2010 EK139 is not well trapped in the 7:2 mean motion resonance in the long term and cannot be trapped simultaneously in von Zeipel–Lidov–Kozai resonance; and finally, we found that at present Eris's longitude of perihelion is stationary, tightly librating around 190°, but unexpectedly loses its confinement, drifting away after 150 Myr, suggesting a missing element in our model.

Keywords: Kuiper belt, Resonant Kuiper belt objects, Pluto, Trans-Neptunian objects, Solar system astronomy
The James Webb Space Telescope Absolute Flux Calibration. II. Mid-infrared Instrument Imaging and Coronagraphy. The absolute flux calibration of the Mid-Infrared Instrument imaging and coronagraphy is based on observations of multiple stars taken during the first 2.5 yr of James Webb Space Telescope operations. The observations were designed to ensure that the flux calibration is valid for a range of flux densities, different subarrays, and different types of stars. The flux calibration was measured by combining observed aperture photometry corrected to infinite aperture with predictions based on previous observations and models of stellar atmospheres. A subset of these observations was combined with model point-spread functions to measure the corrections to infinite aperture. Variations in the calibration factor with time, flux density, background level, type of star, subarray, integration time, rate, and well depth were investigated, and the only significant variations were with time and subarray. Observations of the same star taken approximately every month revealed a modest time-dependent response loss seen mainly at the longest wavelengths. This loss is well characterized by a decaying exponential with a time constant of ∼200 days. After correcting for the response loss, the band-dependent scatter around the corrected average (i.e., repeatability) was found to range from 0.1% to 1.2%. Signals in observations taken with different subarrays can be lower by up to 3.4% compared to FULL frame. After correcting for the time and subarray dependencies, the scatter in the calibration factors measured for individual stars ranges from 1% to 4% depending on the band. The formal uncertainties on the flux calibration averaged for all observations are 0.3%–1.0%, with longer-wavelength bands generally having larger uncertainties.

Keywords: Calibration, Flux calibration
Initial Mass Functions of Young Stellar Clusters from the Gemini Spectroscopic Survey of Nearby Galaxies. I. Young Massive Clusters in the Antennae Galaxies. The stellar initial mass function (IMF) is a key parameter to understand the star formation process and the integrated properties of stellar populations in remote galaxies. We present a spectroscopic study of young massive clusters (YMCs) in the starburst galaxies NGC 4038/9. The integrated spectra of seven YMCs obtained with GMOS-S attached to the 8.1 m Gemini South telescope reveal the spectral features associated with stellar ages and the underlying IMFs. We constrain the ages of the YMCs using the absorption lines and strong emission bands from Wolf─Rayet stars. The internal reddening is also estimated from the strength of the Na I D absorption lines. Based on these constraints, the observed spectra are matched with the synthetic spectra generated from a simple stellar population model. Several parameters of the clusters including age, reddening, cluster mass, and the underlying IMF are derived from the spectral matching. The ages of the YMCs range from 2.5 to 6.5 Myr, and these clusters contain stellar masses ranging from 1.6 × 105 M ☉ to 7.9 × 107 M ☉. The underlying IMFs appear to differ from the universal form of the Salpeter/Kroupa IMF. Interestingly, massive clusters tend to have the bottom-heavy IMFs, although the masses of some clusters are overestimated due to the crowding effect. Based on this, our results suggest that the universal form of the IMF is not always valid when analyzing integrated light from unresolved stellar systems. However, further study with a larger sample size is required to reach a definite conclusion.

Keywords: Stellar mass functions, Starburst galaxies, Star forming regions, Young massive clusters
The Search for the In-betweeners: How Packed Are TESS Planetary Systems?. In this work, we examine seven systems discovered by TESS, to see whether there is any room in those systems for an additional planet (or several) to lurk unseen between the two planets already confirmed therein. In five of those systems (namely, HD 15337, HD 21749, HD 63433, HD 73583, and LTT 3780), we find that there is ample room for an undiscovered planet to move between those that have already been discovered. In other words, as they currently stand, those systems are not tightly packed. In stark contrast, the perturbative influence of the two known TOI-1670 planets is such that additional planets in between are ruled out. The final system, TOI 421, is more challenging. In the vast majority of cases, adding an Earth-mass planet to that system between the orbits of the known planets caused catastrophic instability. Just ∼1.1% of our simulations of the modified system proved dynamically stable on a timescale of 1 Myr. As a result, it seems that there is very little room between the two known planets in the TOI 421 system for an additional unseen world to exist, but the existence of such a planet cannot be definitely ruled out on dynamical grounds alone.

Keywords: Exoplanet dynamics, Astrobiology, Exoplanets
Disequilibrium Chemistry, Diabatic Thermal Structure, and Clouds in the Atmosphere of COCONUTS-2b. Located 10.888 pc from Earth, COCONUTS-2b is a planetary-mass companion to a young (150─800 Myr) M3 star, with a wide orbital separation (6471 au) and a low companion-to-host mass ratio (0.021 ± 0.005). We have studied the atmospheric properties of COCONUTS-2b using newly acquired 1.0─2.5 μm spectroscopy from Gemini/Flamingos-2. The spectral type of COCONUTS-2b is refined to T9.5 ± 0.5 based on comparisons with T/Y dwarf spectral templates. We have conducted an extensive forward-modeling analysis, comparing the near-infrared spectrum and mid-infrared broadband photometry of COCONUTS-2b with 16 state-of-the-art atmospheric model grids developed for brown dwarfs and self-luminous exoplanets near the T/Y transition. The PH  3  -free ATMO2020++, ATMO2020++, and Exo-REM models best match the specific observations of COCONUTS-2b, regardless of variations in the input spectrophotometry. This analysis suggests the presence of disequilibrium chemistry, along with a diabatic thermal structure and/or clouds, in the atmosphere of COCONUTS-2b. All models predict fainter Y-band fluxes than observed, highlighting uncertainties in the alkali chemistry models and opacities. We determine a bolometric luminosity of   dex, with a 0.5 dex wide range of [−6.43, −5.93] dex that accounts for various assumptions of atmospheric models. Using several thermal evolution models, we derive an effective temperature of   K, a surface gravity of   dex, a radius of   R Jup, and a mass of M = 8 ± 2 M Jup. Various atmospheric model grids consistently indicate that COCONUTS-2b's atmosphere likely has subsolar or near-solar metallicity and C/O. These findings provide valuable insights into COCONUTS-2b's formation history and the potential outward migration to its current wide orbit.

Keywords: Y dwarfs, Exoplanet atmospheres, T dwarfs
CRIRES<SUP>+</SUP> and ESPRESSO Reveal an Atmosphere Enriched in Volatiles Relative to Refractories on the Ultrahot Jupiter WASP-121b. One of the outstanding goals of the planetary science community is to measure the present-day atmospheric composition of planets and link this back to formation. As giant planets are formed by accreting gas, ices, and rocks, constraining the relative amounts of these components is critical to understand their formation and evolution. For most known planets, including the solar system giants, this is difficult as they reside in a temperature regime where only volatile elements (e.g., C, O) can be measured, while refractories (e.g., Fe, Ni) are condensed to deep layers of the atmosphere where they cannot be remotely probed. With temperatures allowing for even rock-forming elements to be in the gas phase, ultrahot Jupiter atmospheres provide a unique opportunity to simultaneously probe the volatile and refractory content of giant planets. Here, we directly measure and obtain bounded constraints on the abundances of volatile C and O as well as refractory Fe and Ni on the ultrahot giant exoplanet WASP-121b. We find that ice-forming elements are comparatively enriched relative to rock-forming elements, potentially indicating that WASP-121b formed in a volatile-rich environment much farther away from the star than where it is currently located. The simultaneous constraint of ice and rock elements in the atmosphere of WASP-121b provides insights into the composition of giant planets otherwise unattainable from solar system observations.

Keywords: High resolution spectroscopy, Exoplanet atmospheric composition , Exoplanet atmospheres
Mars Gravity Field Determination Based on Satellite-to-Satellite Tracking Technique. The Martian gravity field serves as the primary constraint for modeling the interior structure and changes in the surface mass. Currently, the determination of the Martian gravity field relies on ground-based tracking measurements, such as range and Doppler, conducted between Earth stations and Mars orbiters. However, these tracking methods encounter limitations in terms of observation accuracy and signal attenuation. Given the successful application of the satellite-to-satellite tracking technique in determining Earth's gravity field, as well as improving the resolution of the lunar gravity field, this paper explores its potential application to the determination of the Martian static gravity field. The objective of this research is to employ numerical simulation to assess the improvement in the precision of the Martian static gravity field achievable with the low–low satellite-to-satellite tracking (ll-SST) technique, considering various conditions, including observation durations, measurement noises, and orbital altitudes. The findings show that the intersatellite ranging system considerably enhances the global resolution of the gravity field, using the ll-SST technique at an orbital altitude of 300 km and a SST measurement noise of 1 μm s‑1, the global resolution can reach at least degree 120. Reducing the measurement noise by an order of magnitude can increase the global resolution of the gravity field by 20 degrees for 300 km altitudes, and 16 degrees for 400 km altitudes. Reducing the orbital altitude by 100 km (from 400 to 300 km) results in a 20 degrees improvement in the global resolution of the gravity field.

Keywords: Gravitational fields
5 cm OH Masers in Northern Star Formation Regions. We present a 6.0 GHz excited-state OH maser survey toward 155 northern star formation regions utilizing the Shanghai Tianma Radio Telescope. In total, we detect 44 6.0 GHz OH masers, 8 of which are new detections (one at 6016 MHz, two at 6030 MHz, and five at 6035 MHz). Of these 44 detected 6.0 GHz OH masers, 13 sites exhibit 6030 MHz OH masers, all 44 sites show the 6035 MHz transition, one site (G009.620+0.194) has the only 6016 MHz OH maser, and one site (W3(OH)) shows the only 6049 MHz OH maser. The 6016 MHz OH maser is the first OH maser of this transition detected in star formation regions. Investigations of the association between 6030/6035 MHz OH masers with 1665 MHz ground-state OH, 6.7 GHz methanol, and 22 GHz water masers show that 1665 MHz OH masers are good indicators of 6.0 GHz OH masers (29% detection rate), which is consistent with previous results. The majority (more than 77%) of 6030 and 6035 MHz OH masers are associated with 6.7 GHz methanol and/or 22 GHz water masers. Comparison between our spectra with previous spectra, we find that only two sources remain fairly stable since their discoveries. We identify 80 Zeeman pairs in 32 6.0 GHz OH maser sites with typical magnetic field strengths of less than 10 mG. The magnetic field directions derived from these 32 maser sites with Zeeman pairs are consistent with previous work, which indicates that the 6.0 GHz OH masers may be potential tracers of the large-scale Galactic magnetic field.

Keywords: Interstellar molecules, Catalogs, Star formation, Interstellar masers