Search Publications
Conditions for galaxy quenching at 0.5 < z < 2.5 from CANDELS: compact cores and environment
Gu, Qiu-Sheng; Gu, Yi-Zhou; Ge, Xue +2 more
We investigate two classes of conditions for galaxy quenching at 0.5 < z < 2.5 based on the structural scaling relations of galaxies in the five Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) fields: the formation of a compact core and the environment. We confirm that in the entire redshift range, massive quiescent …
Spectral properties of the surface reflectance of the northern polar region of Mercury
Diep, Pham Ngoc; Ngoc, Nguyen Bich; Bott, Nicolas
We analyze MESSENGER reflectance measurements covering the northern polar region of Mercury, the least studied region of the northern mercurian hemisphere. We use observations from the Mercury Dual Imaging System Wide-Angle Camera (MDIS/WAC) and the Mercury Atmospheric and Surface Composition Spectrometer (MASCS/VIRS) to study the spectral depende…
A photometric-spectroscopic study of the infrared-excess eclipsing binary V2364 Cyg
Jiang, Lin-Qiao; Dai, Hai-Feng; Wang, Shuang +2 more
The eclipsing binary V2364 Cyg is an A7V-type contact binary with a period of 0.5921 d. We present six spectra from LAMOST and BVRc light curves (LCs), which are simultaneously analyzed to obtain the absolute physical parameters. The first light maxima are brighter than the second ones by up to $\mathrm{0}_{.}^\mathrm{m}{038}$ , $\mathr…
Influence of the convective mixing-length parameter α on the chemical abundances in the case of metal-poor giant HD 122563
Zhao, Gang; Song, Nan; Alexeeva, Sofya
One-dimensional (1D) model atmospheres are still the most commonly used tool for the determination of stellar chemical composition. Convection in the model is usually treated by mixing-length theory (MLT). The mixing-length parameter α is generally calibrated from the Sun and applied to all other stars. The metal-poor giant, HD 122563, is an impor…
Searching for exoplanets by HEPS II. detecting earth-like planets in habitable zone around planet hosts within 30 pc
Yang, Ming; Zhang, Hui; Zhou, Ji-Lin +4 more
HEPS (Habitable ExoPlanet Survey) is a planning astrometry satellite that aims to find Earth-like planets in the solar neighbourhood. In this paper, we selected 140 planet harboring stars within 30 pc of the solar system to be potential targets for HEPS. We calculate the detection probability of the planet in habitable zone (HZ) for each system us…
Binary star detection in the open cluster King 1 field
Saleh, Parvej Reja; Hazarika, Debasish; Dar, Ajaz Ahmad +2 more
A rarely studied open cluster, King 1 is observed using the 1.3-m telescope equipped with a 2k × 4k CCD at Vainu Bappu Observatory, India. We analyze the photometric data obtained from CCD observations in both B and V bands. Out of 132 detected stars in the open cluster King 1 field, we have identified four stellar variables, and two among them ar…
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…