Search Publications
Stellar X-Ray Activity and Habitability Revealed by the ROSAT Sky Survey
Liu, Jifeng; Wang, Song; Li, Xue +3 more
Using the homogeneous X-ray catalog from ROSAT observations, we conducted a comprehensive investigation into stellar X-ray activity–rotation relations for both single and binary stars. Generally, the relation for single stars consists of two distinct regions: a weak decay region, indicating a continued dependence of the magnetic dynamo on stellar …
The Measurement of Masses of OB-type Stars from LAMOST DR5
Liu, Chao; Liu, Zhicun; Cui, Wenyuan +5 more
The measurements of masses and luminosities of massive stars play an important role in understanding the formation and evolution of their host galaxies. In this work, we present the measurement of masses and luminosities of 2946 OB-type stars, including 78 O-type stars and 2868 B-type stars, based on their stellar parameters (effective temperature…
Se-ResNet+SVM Model: An Effective Method of Searching for Hot Subdwarfs from LAMOST
Wu, Tianmin; Yi, Zhenping; Lei, Zhenxin +7 more
This paper presents a robust neural network approach for identifying hot subdwarfs. Our method leveraged the Squeeze-and-Excitation Residual Network to extract abstract features, which were combined with experience features to create hybrid features. These hybrid features were then classified using a support vector machine. To enhance accuracy, we…
An Efficient Method for Batch Derivation of Detached Eclipsing Binary Parameters: Analysis of 34,907 OGLE Systems
Liu, Wei; Ding, Xu; Ji, KaiFan +3 more
Detached eclipsing binary (EB) systems are crucial for measuring the physical properties of stars that evolve independently. Large-scale time-domain surveys have released a substantial number of light curves for detached EBs. Utilizing the Physics of Eclipsing Binaries package in conjunction with Markov Chain Monte Carlo (MCMC) methods for batch p…
Estimating Stellar Atmospheric Parameters and [α/Fe] for LAMOST O-M-type Stars Using a Spectral Emulator
Luo, A. -Li; Li, Yin-Bi; Kong, Xiao +7 more
In this paper, we developed a spectral emulator based on the Mapping Nearby Galaxies at Apache Point Observatory Stellar Library (MaStar) and a grouping optimization strategy to estimate effective temperature (T eff), surface gravity (log g), metallicity ([Fe/H]), and the abundance of alpha elements with respect to iron ([α/Fe]) for O-M…
X-Ray Emission of Nearby Low-mass and Sunlike Stars with Directly Imageable Habitable Zones
Peacock, Sarah; Kane, Stephen R.; Schwieterman, Edward W. +5 more
Stellar X-ray and UV radiation can significantly affect the survival, composition, and long-term evolution of the atmospheres of planets in or near their host star's habitable zone (HZ). Especially interesting are planetary systems in the solar neighborhood that may host temperate and potentially habitable surface conditions, which may be analyzed…
LEAVES: An Expandable Light-curve Data Set for Automatic Classification of Variable Stars
Chen, Xiaodian; Fei, Ya; Yu, Ce +6 more
With the increasing amount of astronomical observation data, it is an inevitable trend to use artificial intelligence methods for automatic analysis and identification of light curves for full samples. However, data sets covering all known classes of variable stars that meet all research needs are not yet available. There is still a lack of standa…
Physical Parameters and Magnetic Activity of M-type Stars Based on the LAMOST DR9, SDSS, and TESS Surveys
Han, Xianming L.; Misra, Prabhakar; Zhang, Li-yun +3 more
We analyze a catalog comprising 781,232 spectra from 641,095 M dwarf stars from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) low-resolution spectroscopic data release 9. Based on the equivalent width of the Hα line, we ascertain the activity properties of the stars, identifying a total of 107,134 active stars, with 31,175…
Atomic Transition Probabilities for Ultraviolet and Optical Lines of Tm II
Roederer, I. U.; Den Hartog, E. A.; Voith, G. T.
We report new branching fraction measurements for 224 ultraviolet and optical transitions of Tm II. These transitions range in wavelength (wavenumber) from 2350 to 6417 Å (42,532–15,579 cm‑1) and originate in 13 odd-parity and 24 even-parity upper levels. Thirty-five of the 37 levels, accounting for 213 of the 224 transitions, are studi…
The Value-added Catalog of OB Stars in LAMOST DR7
Shi, Jianrong; Liu, Zhicun; Cui, Wenyuan +4 more
In this work, we update the catalog of OB stars based on the Large Sky Area Multi-Object Fiber Spectroscopic Telescope data release 7 and modify the OB stars' selection criteria in spectral line indices' space. The new catalog includes 37,778 spectra of 27,643 OB stars, of which 3827 OB stars are newly identified. The spectral subclasses of 27,643…