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HdC and EHe stars through the prism of Gaia DR3. 3D distribution and Gaia's chromatic PSF effects
Tisserand, P.; Crawford, C. L.; Clayton, G. C. +3 more
Context. Upon its release the Gaia DR3 catalogue has led to tremendous progress in multiple fields of astronomy by providing the complete astrometric solution for nearly 1.5 billion sources.
Aims: We analysed the photometric and astrometric results for Hydrogen-deficient Carbon (HdC), Extreme Helium (EHe), and DYPer type stars to identify any…
tdescore: An Accurate Photometric Classifier for Tidal Disruption Events
Rusholme, Ben; Sollerman, Jesper; van Velzen, Sjoert +12 more
Optical surveys have become increasingly adept at identifying candidate tidal disruption events (TDEs) in large numbers, but classifying these generally requires extensive spectroscopic resources. Here we present tdescore, a simple binary photometric classifier that is trained using a systematic census of ∼3000 nuclear transients from the Zwicky T…
Flaring Stars in a Nontargeted Millimeter-wave Survey with SPT-3G
Ade, P. A. R.; Benabed, K.; Bouchet, F. R. +96 more
We present a flare star catalog from 4 yr of nontargeted millimeter-wave survey data from the South Pole Telescope (SPT). The data were taken with the SPT-3G camera and cover a 1500 deg2 region of the sky from 20h40m0s to 3h20m0s in right ascension and from ‑42° to ‑70° i…
The Ice Chemistry in Comets and Planet-forming Disks: Statistical Comparison of CH3OH, H2CO, and NH3 Abundance Ratios
Ceccarelli, Cecilia; Codella, Claudio; Villanueva, Geronimo L. +5 more
Comets are frozen remnants of our solar system's formation, and comparing their chemical composition to that of planet-forming systems can reveal crucial insights about our origins, potentially answering one of the most challenging questions in planetary science, i.e., whether cometary material was mainly inherited from the protosolar nebula or re…
The Uranus system from occultation observations (1977-2006): Rings, pole direction, gravity field, and masses of Cressida, Cordelia, and Ophelia
Nicholson, Philip D.; French, Richard G.; Hedman, Matthew M. +2 more
From an analysis of 31 Earth-based stellar occultations and three Voyager 2 occultations spanning 1977-2006 (French et al. 2023a), we determine the keplerian orbital elements of the centerlines of the nine main Uranian rings to high accuracy, with typical RMS residuals of 0.2-0.4 km and 1- σ formal errors in a , ae , and a sin i of order 0.1 km, r…
CANUCS: UV and ionizing properties of dwarf star-forming galaxies at z 5-7
Willott, Chris J.; Harshan, Anishya; Martis, Nicholas S. +14 more
The epoch of reionization (EoR) progressed through the emission of ionizing photons from galaxies to their local intergalactic medium. In this work, we characterize the dwarf star-forming galaxies as candidates for the source of ionizing photons that drove EoR. We investigate the ionizing properties and star formation histories of star-forming dwa…
The white dwarf binary pathways survey - X. Gaia orbits for known UV excess binaries
Gänsicke, B. T.; Koester, D.; Rebassa-Mansergas, A. +9 more
White dwarfs with an F, G, or K type companion represent the last common ancestor for a plethora of exotic systems throughout the galaxy, though to this point very few of them have been fully characterized in terms of orbital period and component masses, despite the fact several thousand have been identified. Gaia data release 3 has examined many …
GRB 240529A: A Tale of Two Shocks
Fang, Min; Liu, Hao; Liu, Wei +66 more
Thanks to the rapidly increasing time-domain facilities, we are entering a golden era of research on gamma-ray bursts (GRBs). In this Letter, we report our observations of GRB 240529A with the Burst Optical Observer and Transient Exploring System, the 1.5 m telescope at Observatorio de Sierra Nevada, the 2.5 m Wide Field Survey Telescope of China,…
New Insights into the Internal Structure of GJ 1214 b Informed by JWST
Eastman, Jason D.; Bean, Jacob L.; Zhang, Michael +7 more
Recent JWST observations of the sub-Neptune GJ 1214 b suggest that it hosts a high-metallicity (≳100× solar), hazy atmosphere. Emission spectra of the planet show molecular absorption features, most likely due to atmospheric H2O. In light of this new information, we conduct a thorough reevaluation of the planet's internal structure. We …
Stellar Evolution in Real Time. II. R Hydrae and an Open-Source Grid of >3000 Seismic TP-AGB Models Computed with MESA
Tayar, Jamie; Joyce, Meridith; Molnár, László +3 more
We present a comprehensive characterization of the evolved thermally pulsing asymptotic giant branch (TP-AGB) star R Hydrae (R Hya), building on the techniques applied in Stellar Evolution in Real Time I (Molnár et al.) to T Ursae Minoris. We compute over 3000 theoretical TP-AGB pulse spectra using MESA and the corresponding oscillation spectra wi…