相关论文: High-velocity moving groups in the Solar neighborh…

While spectroscopically characterizing nearby ultracool dwarfs discovered in the Gaia Second Data Release with the TripleSpec spectrograph on the Palomar 200'' telescope, we encountered a particularly cool, nearby, new member of the solar…

Binary and multiple stars have long provided an effective empirical method of testing stellar formation and evolution theories. In particular, the existence of wide binary systems (separations $>$20,000 au) is particularly challenging to…

The second data release from the Gaia mission (DR2) provides a comprehensive and unprecedented picture of the motions of astronomical sources in the plane of the sky, extending from the solar neighborhood to the outer reaches of the Milky…

The Milky Way halo is one of the few galactic haloes that provides a unique insight into galaxy formation by resolved stellar populations. Here, we present a catalogue of $\sim$47 million halo stars selected independent of parallax and…

Aims: With the latest Gaia DR3 data, we analyse the widest pairs in the Washington Double Star (WDS) catalogue with angular separations, $\rho$, greater than 1000 arcsec. Methods: We confirmed the pair's membership to stellar systems based…

The publications of Gaia DR2 and DR3 have brought major improvements in stellar astrometry and photometry, particularly regarding the description of the white dwarf sequence. Notably, Gaia DR2 enabled the detection of variability in white…

To determine the velocity ellipsoid of the solar neighborhood white dwarfs, we use the space velocity components of stars. Two samples of white dwarfs are used, 20 pc and 25 pc samples. Beside the two main samples, the solar velocity and…

We use about 200,000 FGK type main-sequence stars from the LAMOST DR1 data to map the local stellar kinematics. With the velocity de-projection technique, we are able to derive the averaged 3 dimensional velocity and velocity ellipsoids…

Under Newtonian dynamics, the relative motion of the components of a binary star should follow a Keplerian scaling with separation. Once orientation effects and a distribution of ellipticities are accounted for, dynamical evolution can be…

This research note presents a comparison of radial velocities between the RAVE DR5 data release with Gaia DR2. RAVE DR5 and Gaia DR2 have 450587 stars in common. In particular we would like to shed light on a small subset of joint targets…

We present a novel method to detect variable astrophysical objects and transient phenomena using anomalous excess scatter in repeated measurements from public catalogs of Gaia DR2 and Zwicky Transient Facility (ZTF) DR3 photometry. We first…

We detail an innovative new technique for measuring the 2-D velocity moments (rotation velocity, velocity dispersion and Gauss-Hermite coefficients h$_3$ and h$_4$) of the stellar populations of galaxy halos using spectra from Keck DEIMOS…

Clumps in the solar neighborhood's stellar velocity distribution could be caused by spiral density waves. In the solar neighborhood, stellar velocities corresponding to orbits that are nearly closed in the frame rotating with a spiral…

The absolute number and the density profiles of different types of stars in the solar neighborhood are a fundamental anchor for studies of the initial mass function, stellar evolution, and galactic structure. Using data from the Gaia DR1…

Passing stars may play an important role in the evolution of our solar system. We search for close stellar encounters to the Sun among all 7.2 million stars in Gaia-DR2 that have six-dimensional phase space data. We characterize encounters…

The stellar velocity distribution in the Solar Neighbourhood displays kinematic substructures, which are possibly signatures of the bar and spiral arms of the Milky Way and of previous accretion events. These kinematic substructures --…

A proper understanding of the Milky Way (MW) dwarf galaxies in a cosmological context requires knowledge of their 3D velocities and orbits. However, proper motion (PM) measurements have generally been of limited accuracy and available only…

Aims. The Radial Velocity Spectrometer (RVS) on board the ESA satellite mission Gaia has no calibration device. Therefore, the radial velocity zero point needs to be calibrated with stars that are proved to be stable at a level of 300 m/s…

We analyze 9 open clusters with ages in the range 70 Myr to 3.2 Gyr using UCAC2 proper motion data and 2MASS photometry. For each cluster we consider the projected velocity distributions in the core and off-core regions separately. In the…

The Gaia DR2 sample of short-timescale variable candidates results from the investigation of the first 22 months of Gaia photometry for a subsample of sources at the Gaia faint end. For this exercise, we limited ourselves to the case of…