Search Publications
More than two hundred and fifty thousand spectroscopic binary or variable star candidates discovered by LAMOST
Li, Lin-Jia; Qian, Sheng-Bang; Zhu, Li-Ying +7 more
About 786.4 thousand stars were observed by LAMOST twice or more during the first stage of its spectroscopic survey. The radial velocity differences for about 256 thousand targets are larger than 10 km s-1 and they are possible spectroscopic binary or variable candidates (SBVCs). It is shown that most SBVCs are slightly metal poorer tha…
The W UMa binaries USNO-A2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac: light curve solutions and global parameters based on Gaia distances
Popov, Velimir A.; Petrov, Nikola I.; Kjurkchieva, Diana P. +1 more
We present photometric observations in Sloan filters g‧, i‧ of the eclipsing W UMa stars USNO-A2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac. The sinusoidal-like O - C diagram of V471 Cas indicates the presence of a third body with mass 0.12 M ⊙ (a red dwarf) at distance 897 R ⊙. The O - C diagram of V479 Lac reveals a p…
Local standard of rest based on Gaia DR2 catalog
Zhu, Zi; Liu, Jia-Cheng; Ding, Ping-Jie
The local standard of rest (LSR) provides a reference framework for studies of Galactic kinematics. Determination of the LSR corresponds to the measurement of solar peculiar motion, which is under debate due to the fact that different methods and samples have been used. Adopting the astrometric data and line-of-sight velocities of main sequence st…
Photometric investigations on two totally eclipsing contact binaries: V342 UMa and V509 Cam
Zhang, Yu; Li, Kai; Xia, Qi-Qi +6 more
By analyzing two sets of complete BVRcIc light curves for V342 UMa and three sets of complete BVRcIc light curves for V509 Cam, we determined that the two systems are both W-subtype contact binaries and that V342 UMa manifests a shallow contact configuration, while V509 Cam exhibits a medium contact conf…
A compilation of known QSOs for the Gaia mission
Liao, Shi-Long; Qi, Zhao-Xiang; Guo, Su-Fen +1 more
Quasars are essential for astrometry in the sense that they are spatially stationary because of their large distance from the Sun. The European Space Agency (ESA) astrometric satellite Gaia is scanning the whole sky with unprecedented accuracy up to the level of a few µas. However, Gaia’s two-fields-of-view-observation strategy may introduce…
Physical properties of γ Doradus pulsating stars and their relationship with long-period δ Scuti variables
Li, Lin-Jia; Qian, Sheng-Bang; Zhu, Li-Ying +3 more
We present LAMOST data on 168 γ Doradus (γ Dor) pulsating stars including stellar atmospheric parameters of 137 variables and spectral types for all of the samples. The distributions of period (P), temperature (T), gravitational acceleration (log(g)) and metallicity [Fe/H] are shown. It is found that most γ Dor variables are main-sequence stars wi…
Orbital and physical parameters of the close binary system GJ 9830 (HIP 116259)
Al-Wardat, Mashhoor A.; Pathan, J. M.; Masda, Suhail G.
We present the complete set of physical and geometrical parameters of the visual close binary system GJ 9830 for the first time by applying Al-Wardat’s complex method. This method combines magnitude difference from speckle interferometry, synthetic spectral energy distributions of the binary components which are constructed based on grids of Kuruc…
A catalog of DB white dwarfs from the LAMOST DR5 and construction of templates
Luo, A. -Li; Kong, Xiao; Li, Xiang-Ru
In this study, we employ machine learning to build a catalog of DB white dwarfs (DBWDs) from the LAMOST Data Release (DR) 5. Using known DBs from SDSS DR14, we selected samples of high-quality DB spectra from the LAMOST database and applied them to train the machine learning process. Following the recognition procedure, we chose 351 DB spectra of …
New photometric investigation of the low-mass-ratio contact binary star V1853 Orionis
Qian, Sheng-Bang; He, Jia-Jia; Sarotsakulchai, Thawicharat +3 more
Four-color charge-coupled device (CCD) light curves in the B, V, Rc and Ic bands of the total-eclipsing binary system V1853 Orionis (V1853 Ori) are presented. By comparing our light curves with those published by previous investigators, it is determined that the O’Connell effect on the light curves has disappeared. By analyzing those multi-color l…
Galactic halo age estimated from LAMOST DR4 and Gaia DR1
Yuan, Hai-Bo; Huang, Yang; Chen, Bing-Qiu +8 more
The stellar halo is one of the major components in the Milky Way. Research on its age can provide critical constraints on the origin of the stellar halo and further on the formation of our Galaxy. So far, different approaches and samples have been used to estimate the age of the Galactic halo. In our previous paper, we carefully selected 63 field …