Related papers: On the accuracy of close stellar approaches determ…
We introduce a method of measuring a lower limit to the amplitude of surface differential rotation from high-precision, evenly sampled photometric time series. It is applied to main-sequence late-type stars whose optical flux modulation is…
Proper motion studies of stars in the centre of the Milky Way have been typically limited to the Arches and Quintuplet clusters and to the central parsec. Here, we present the first results of a large-scale proper motion study of stars…
Context: Stellar clusters are benchmarks for theories of star formation and evolution. The high precision parallax data of the Gaia mission allows significant improvements in the distance determination to stellar clusters and its stars. In…
Astrometry is one of the oldest branches of astronomy which measures the position, the proper motion and parallax of celestial objects. Following the Hipparcos and Gaia missions that have measured several billions of them using global…
We propose a kinematic approach to searching for the stars that could be formed with the Sun in a common "parent" open cluster. The approach consists in preselecting suitable candidates by the closeness of their space velocities to the…
The global astrometric observations of a GAIA-like satellite were modeled within the PPN formulation of Post-Newtonian gravitation. An extensive experimental campaign based on realistic end-to-end simulations was conducted to establish the…
Stellar mass is a fundamental parameter that is key to our understanding of stellar formation and evolution, as well as the characterization of nearby exoplanet companions. Historically, stellar masses have been derived from long-term…
For more than fifty years, astronomers have mapped the neutral hydrogen gas in the Galaxy assuming kinematically derived distances. We employ the distances of nearby young stars, which trace the gas from which they formed, in…
We combine Gaia DR1, PS1, SDSS and 2MASS astrometry to measure proper motions for 350 million sources across three-fourths of the sky down to a magnitude of $m_r\sim20$\,. Using positions of galaxies from PS1, we build a common reference…
Sun-like stars are a new probe of variations in the fine-structure constant, $\alpha$, via the solar twins approach: velocity separations of close pairs of absorption lines are compared between stars with very similar stellar parameters,…
In this paper we present and analyse determinations of effective temperatures of planet-hosting stars using infrared (IR) photometry. One of our goals is the comparison with spectroscopic temperatures to evaluate the presence of systematic…
We predict the distinctive three dimensional space motions of hypervelocity stars (HVSs) and runaway stars moving in a realistic Galactic potential. For nearby stars with distances less than 10~kpc, unbound stars are rare; proper motions…
High-precision astrometry well beyond the capacities of Gaia will provide a unique way to achieve astrophysical breakthroughs, in particular on the nature of dark matter, and a complete survey of nearby habitable exoplanets. In this…
Adding an independent estimate of the mean stellar density, $\rho_{\star}$, as a constraint in the analysis of stars that host transiting exoplanets can significantly improve the precision of the planet radius estimate in cases where the…
The kinematic parameters identified from high-velocity stars situated within 100 kpc are examined and analyzed. We included three high velocity programs comprising 591, 87, and 519 stars as a function of distances ranging from 0.10 to…
Stellar inclination is an important parameter for many astrophysical studies. Although different techniques allow us to estimate stellar inclinationt for fast rotators, it becomes much more difficult when stars are rotating slower than…
We provide a catalogue of pairs of stars whose periapses are less than 1pc within the past or future 100 Myr. We use astrometric data from TGAS, Hipparcos and radial velocity data from RAVE and XHIP to find the space motions and hence the…
We describe a homogeneous catalog compilation of common proper motion stars based on Gaia DR2. A preliminary list of all pairs of stars within the radius of 100 pc around the Sun with a separation less than a parsec was compiled. Also, a…
We evaluate the potential of the ESA Cornerstone Mission GAIA in helping populate the database of nearby stars ($d < 25$ pc) for subsequent target selection for DARWIN/TPF. The GAIA high-precision astrometric measurements will make it an…
High proper motion stars probe several extreme stellar populations, including nearby objects, Galactic halo stars, and hyper-velocity stars. Extending the search for high proper motion stars, to faint limits can increase their numbers and…