Related papers: Dynamically Tagged Groups of Metal-Poor Stars II. …

We report estimated carbon-abundance ratios, [C/Fe], for seven newly-discovered carbon-enhanced metal-poor (CEMP) RR Lyrae stars. These are well-studied RRab stars that had previously been selected as CEMP candidates based on low-resolution…

Large numbers of low-to-medium resolution spectra of M-type dwarf stars from both the local Galactic disk and halo are available from various surveys. In order to fully exploit these data, we develop a template-fit method using a set of…

We present a detailed study of the chemical diversity of the metal-poor Milky Way (MW) using data from the GALAH DR3 survey. Considering 17 chemical abundances relative to iron ([X/Fe]) for 9,923 stars, we employ Principal Component…

We applied Stars' Galactic Origin (StarGO) algorithm in 7D space (i.e., [Fe/H], [Mg/Fe], [Al/Fe], $L_{z}$, $J_{r}$, $J_{z}$, $E$) to analyze stars in the inner halo with APOGEE DR17. We identified some known substructures, including…

Based on the data release of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope survey (LAMOST DR5) and the \emph{Gaia} Early Data Release 3 (\emph{Gaia} EDR3), we construct a sample containing 46,109 giant (log~$\emph{g}$…

Most of known RR Lyraes are type ab RR Lyraes (RRLab), and they are the excellent tool to map the Milky Way and its substructures. We find that 1148 RRLab stars determined by Drake et al.(2013) have been observed by spectroscopic surveys of…

RR Lyrae stars (RRLs) are old pulsating variables widely used as metallicity tracers due to the correlation between their metal abundances and light curve morphology. With ESA Gaia DR3 providing light curves for about 270,000 RRLs, there is…

Metal-poor stars are important tools for tracing the early history of the Milky Way, and for learning about the first generations of stars. Simulations suggest that the oldest metal-poor stars are to be found in the inner Galaxy. Typical…

The metal-poor stars of a galaxy offer insights into that galaxy's early formation processes and accretion history. Here, we investigate whether the metal-poor stars of our Milky Way galaxy exhibit any characteristic trends in…

We present the latest results of our ongoing multiplicity study of (Community) TESS Objects of Interest, using astrometric and photometric data from the ESA-Gaia mission to detect stellar companions of these stars and characterize their…

The combination of the final version of the RAVE spectroscopic survey data release 6 with radial velocities and astrometry from Gaia DR2 allows us to identify and create a catalog of single lined binary star candidates (SB1), their inferred…

Population-level studies of Milky Way satellites used to constrain dark matter or the threshold of galaxy formation often rely on velocity dispersions and metallicities derived from heterogeneous spectroscopic analyses. Systematic…

This work explores dynamical models of the Milky Way (MW) by analyzing a sample of 86,109 K giant stars selected through cross-matching the LAMOST DR8 and Gaia EDR3 surveys. Our earlier torus models in Wang et al. (2017) did not include…

We use photometric metallicity estimates for about 700000 stars in the surroundings of the Sun, with very accurate distances and 3-D motions measures from Gaia DR3, to explore the properties of the metal-poor (-2.0<[Fe/H]<= -1.5; MP) and…

We present new metallicity measurements for 298 individual red giant branch stars in eight of the least luminous dwarf spheroidal galaxies (dSphs) in the Milky Way (MW) system. Our technique is based on medium resolution Keck/DEIMOS…

(Abridged) We analyzed the stellar parameters and radial velocities of ~1200 stars in five bulge fields as determined from the Gaia-ESO survey data (iDR1). We use VISTA Variables in The Via Lactea (VVV) photometry to obtain reddening values…

We present a Bayesian method to cross-match 5,827,988 high proper motion Gaia sources ($\mu>40 \ mas \ yr^{-1}$) to various photometric surveys: 2MASS, AllWISE, GALEX, RAVE, SDSS and Pan-STARRS. To efficiently associate these objects across…

The Milky Way has a large population of dwarf galaxy satellites. Their properties are sensitive to both cosmology and the physical processes underlying galaxy formation, but these properties are still not properly characterized for the…

We report discovery and spectroscopic follow-up of 21 astrometric binaries containing solar-type stars and dark companions with masses near 1.4 $M_{\odot}$. The simplest interpretation is that the companions are dormant neutron stars (NSs),…

Unevolved metal poor stars are the witness of the early evolution of the Galaxy. The determination of their detailed chemical composition is an important tool to understand the chemical history of our Galaxy. The study of their chemical…