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Old Dogs, New Tricks: Re-examining Photographic Spectra of Plaskett's Star
Davidge, T. J.
Photographic spectra of Plaskett's Star (HR 2420, HD 47129, V640 Monocerotis) that were recorded at the Dominion Astrophysical Observatory have been digitized with a flatbed scanner. Many of the spectra were recorded during campaigns in 1922 and 1937, and cover wavelengths between 0.39 and 0.50 µm. Spectra of poor quality are identified. Mea…
Star Proper Motions Based on Two-epoch Observations from the SDSS and DESI Imaging Surveys
Feng, Lu; Zou, Hu; Singh, Gaurav +9 more
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…
Long-term X-Ray Variability on the Benchmark YSO HL Tau
Schneider, P. C.; Kastner, Joel H.; Principe, David A. +4 more
HL Tau is one of the most well-studied Class I young stellar objects (YSOs), including frequent observations at near- and mid-infrared, (sub)millimeter, and X-ray wavelengths. We present the results of an X-ray variability monitoring campaign with XMM-Newton in 2020 and X-ray grating spectroscopy from Chandra/HETGS in 2018. We find that the X-ray …
Analysis of the Gaia Data Release 3 Parallax Bias at Bright Magnitudes
Ding, Ye; Liao, Shilong; Wen, Shangyu +1 more
The combination of visual and spectroscopic orbits in binary systems enables precise distance measurements without additional assumptions, making them ideal for examining the parallax zero-point offset (PZPO) at bright magnitudes (G < 13) in Gaia. We compiled 249 orbital parallaxes from 246 binary systems and used Markov chain Monte Carlo simul…
An In-depth Investigation of the Primordial Cluster Pair ASCC 19 and ASCC 21
Hu, Qingshun; Luo, Yangping; Li, Yuting +4 more
Utilizing Gaia data from the literature, we report a new young (∼8.9 Myr) cluster pair, ASCC 19 and ASCC 21, located near the Orion star-forming complex. The clusters are separated by a 3D distance of 27.00 ± 7.51 pc. Both clusters share a common age (Log(age) = 6.95 ± 0.05), similar radial velocities (RV = 21.34 ± 4.47 km s‑1 for ASCC …
SDSS J100711.74+193056.2: A Candidate Common Motion Substellar Companion to the Nearest B-type Star Regulus
Burgasser, Adam J.; Mamajek, Eric E.
The L9 dwarf SDSS J100711.74+193056.2 is situated 7
PhotoD with LSST: Stellar Photometric Distances Out to the Edge of the Galaxy
Jurić, Mario; Ivezić, Željko; Jurkić, Tomislav +14 more
As demonstrated with the Sloan Digital Sky Survey (SDSS), Pan-STARRS, and most recently with Gaia data, broadband near-UV to near-IR stellar photometry can be used to estimate distance, metallicity, and interstellar dust extinction along the line of sight for stars in the Galaxy. Anticipating photometric catalogs with tens of billions of stars fro…
New Stellar Parameters, Metallicities, and Elemental Abundance Ratios for 311 Metal-poor Stars
Roederer, Ian U.; Mittal, Sanil
We present equivalent widths, improved model atmosphere parameters, and revised abundances for 14 species of 11 elements derived from high-resolution optical spectroscopy of 311 metal-poor stars. All of these stars had their parameters previously published by Roederer et al. We use color–Teff relationships calibrated for Gaia and 2MASS …
Photometric and Spectroscopic Investigations of Three Large Amplitude Contact Binaries
Li, Kai; Gao, Xing; Liu, Fei +8 more
We performed photometric and spectroscopic studies of three large amplitude contact binaries: NSVS 2418361, ATLAS J057.1170+31.2384, and NSVS 7377875. The amplitudes of these three systems' light curves are more than 0.7 mag. We analyzed the light curves using the Wilson–Devinney code to yield physical parameters. The photometric solutions suggest…
Evidence for Primordial Alignment II: Insights from Stellar Obliquity Measurements for Hot Jupiters in Compact Multiplanet Systems
Rice, Malena; Zhou, George; Huang, Chelsea X. +5 more
A significant fraction of hot Jupiters have orbital axes misaligned with their host stars' spin axes. The large stellar obliquities of these giants have long been considered potential signatures of high-eccentricity migration, which is expected to clear out any nearby planetary companions. This scenario requires that only isolated hot Jupiters be …