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Giant Outer Transiting Exoplanet Mass (GOT 'EM) Survey. IV. Long-term Doppler Spectroscopy for 11 Stars Thought to Host Cool Giant Exoplanets
Mayo, Andrew W.; Rice, Malena; Kane, Stephen R. +29 more
Discovering and characterizing exoplanets at the outer edge of the transit method's sensitivity has proven challenging owing to geometric biases and the practical difficulties associated with acquiring long observational baselines. Nonetheless, a sample of giant exoplanets on orbits longer than 100 days has been identified by transit hunting missi…
A λ 3 mm Line Survey toward the Circumstellar Envelope of the Carbon-rich AGB Star IRC+10216 (CW Leo)
Zhang, Yong; Zhou, Jianjun; Szczerba, Ryszard +14 more
We present an unbiased λ 3 mm spectral line survey (between 84.5 and 115.8 GHz), conducted by the Purple Mountain Observatory 13.7 m radio telescope, together with updated modeling results, toward the carbon-rich asymptotic giant branch star IRC+10216 (CW Leo). A total of 75 spectral lines (96 transitions) are detected, and identified to arise fro…
Relations of Rotation and Chromospheric Activity to Stellar Age for FGK Dwarfs from Kepler and LAMOST
Xiang, Maosheng; Bi, Shaolan; Li, Yaguang +9 more
The empirical relations between rotation period, chromospheric activity, and age can be used to estimate stellar age. To calibrate these relations, we present a catalog, including the masses and ages of 52,321 FGK dwarfs, 47,489 chromospheric activity index $\mathrm{log}{R}_{\mathrm{HK}}^{+}$ , 6077 rotation periods P rot, and variabili…
Projected Rotational Velocities for LAMOST Stars with Effective Temperatures Lower than 9000 K
Luo, A. -Li; Kong, Xiao; Li, Yinbi +5 more
In Data Release 9 of LAMOST, we present measurements of v sin i for a total of 121,698 stars measured using the Medium Resolution Spectrograph (MRS) and 80,108 stars using the Low Resolution Spectrograph (LRS). These values were obtained through a χ 2 minimization process, comparing LAMOST spectra with corresponding grids of synthetical…
He-rich Hot Subdwarf Stars Observed in Gaia DR3 and LAMOST DR7: Carbon and Nitrogen Abundances and Kinematics
Luo, Yangping; Németh, Péter; Wang, Kun +1 more
We conducted an analysis of the abundances of He, C, and N in 210 He-rich hot subdwarfs observed within both the Gaia Data Release 3 (DR3) and LAMOST DR7 data sets. This analysis involved fitting the LAMOST spectra with TLUSTY/SYNSPEC non-LTE synthetic spectra. By examining the Galactic spatial positions, velocity vectors, and orbital parameters o…
Erratum: "Stellar Loci. VII. Photometric Metallicities of 5 Million FGK Stars Based on GALEX GR6+7 AIS and Gaia EDR3" (2024, ApJS, 271, 26)
Huang, Yang; Beers, Timothy C.; Yuan, Haibo +5 more
We combine photometric data from GALEX GR6+7 AIS and Gaia EDR3 with stellar parameters from the SAGA and PASTEL catalogs to construct high-quality training samples for dwarfs ($\rm 0.4< BP-RP<1.6$) and giants ($\rm 0.6< BP-RP <1.6$). We apply careful reddening corrections using empirical temperature- and extinction-dependent extinction…
Magnetic Activity of Millions of G-type Stars Based on the LAMOST DR10 Low-resolution Spectral and TESS Light-curve Surveys and the Future CSST Survey
Han, Xianming L.; Misra, Prabhakar; Zhang, Li-yun +5 more
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) data release 10 (DR10) provides over 3 million G-type stellar spectra, which are important for the study of chromospheric activity of solar-like stars. We have used the iSpec program to perform spectral subtraction on the G-type stellar spectra obtained from LAMOST DR10 with a …
Double-lined Spectroscopic Binaries from the LAMOST Low-resolution Survey
Ting, Yuan-Sen; Liu, Junhui; Zhang, Bo +1 more
We report on a data-driven spectral model that we have developed for the identification of double-lined spectroscopic binary stars (SB2s) in the Large Sky Area Multi-Object fiber Spectroscopic Telescope low-resolution survey (R ∼ 1800). Employing simultaneous fitting with both single-star and binary-star models, we detected over 4800 SB2 candidate…
A Deep Redshift Survey of the Perseus Cluster (A426): Spatial Distribution and Kinematics of Galaxies
Park, Byeong-Gon; Hwang, Narae; Hwang, Ho Seong +3 more
We study the global kinematics of the Perseus galaxy cluster (A426) at redshift z = 0.017 using a large sample of galaxies from our new MMT/Hectospec spectroscopic observation for this cluster. The sample includes 1447 galaxies with measured redshifts within 60' from the cluster center (1148 from this MMT/Hectospec program and 299 from the literat…
A Catalog of Early-type Runaway Stars from LAMOST DR8
Wang, Luqian; Liu, Chao; Wu, You +3 more
Runaway stars are OB-type stars ejected from their birthplace with large peculiar velocities. The leading hypothesis addressed in their formation includes the supernova ejection mechanism and the dynamic ejection scenario. Identification of runaway populations is the first step to investigating their formation and evolution. Here we present our wo…