Related papers: Gaia and brown dwarfs from Spain
This paper uses the multi-epoch astrometry from the Wide-field Infrared Survey Explorer (WISE) to demonstrate a method to measure proper motions and trigonometric parallaxes with precisions of $\sim$4 mas yr$^{-1}$ and $\sim$7 mas,…
The presence of brown dwarfs in the dark galactic halo could be detected through their gravitational lensing effect and experiments under way monitor about one million stars to observe a few lensing events per year. We show that if the…
The measurement of the positions, distances, motions and luminosities of stars represents the foundations of modern astronomical knowledge. Launched at the end of the eighties, the ESA Hipparcos satellite was the first space mission…
The Gaia satellite will be launched at the end of 2011. It will observe at least 1 billion stars, and among them several million emission line stars and hot stars. Gaia will provide parallaxes for each star and spectra for stars till V…
The third data release of Gaia introduced a large catalog of astrometric binaries, out of which about 3,200 are likely main-sequence stars with a white-dwarf (WD) companion. These binaries are typically found with orbital separations of ~1…
The ESA Gaia mission will provide a multi-epoch database for a billion of objects, including variable objects that comprise stars, active galactic nuclei and asteroids. We highlight a few of Gaia's properties that will benefit the study of…
We present the results of a multiband survey for brown dwarfs in the Chamaeleon I dark cloud with the Wide Field Imager (WFI) camera at the ESO/MPG 2.2-m telescope on La Silla (Chile). The survey has revealed a substantial population of…
We discuss the impact that Gaia, a European Space Agency (ESA) cornerstone mission that has been in scientific operations since July 2014, is expected to have on the definition of the cosmic distance ladder and the study of resolved stellar…
Thanks to Gaia and large-scale spectroscopic follow-up surveys (4MOST, DESI, WEAVE, SDSS-V), it is now possible to build representative and minimally biased samples of the local white dwarf population. Here we analyse several volume-limited…
Astrometry from space has unique advantages over ground-based observations: the all-sky coverage, relatively stable, and temperature and gravity invariant operating environment delivers precision, accuracy and sample volume several orders…
Astrometric noise in excess of parallax and proper motion could be a signature of orbital wobble of individual components in binary star systems. The combination of X-ray selection with astrometric noise can then be a powerful tool for…
The ESA Cornerstone Mission GAIA, to be launched prior to 2012 and with a nominal lifetime of 5 years, will improve the accuracy of Hipparcos astrometry by more than two orders of magnitude. GAIA high-precision global astrometric…
One of the fundamental questions in star formation is whether or not brown dwarfs form in the same way as stars, or more like giant planets. If their formation scenarios are different, we might expect brown dwarfs to have a different…
Hidden within the Gaia satellite's multiple data releases lies a valuable cache of dark companions. To facilitate the efficient and reliable detection of these companions via combined analyses involving Gaia, Hipparcos, and Tycho-2…
Gaia is a cornerstone mission of the European Space Agency (ESA) selected in 2000, with a target launch date of 2011. The Gaia mission will perform a survey of about 1 billion sources brighter than V=20. Its goal is to provide astrometry…
The Gaia Data Release 1 (DR1) sample of white dwarf parallaxes is presented, including 6 directly observed degenerates and 46 white dwarfs in wide binaries. This data set is combined with spectroscopic atmospheric parameters to study the…
As the most ancient branch of astronomy, astrometry has been developed for thousands of years. However, it has only recently become possible to utilize astrometry for the detection of exoplanets. Gaia, an astrometric surveyor of 1 billion…
Satellites around substellar companions are a heterogeneous class of objects with a variety of different formation histories. Focusing on potentially detectable satellites around exoplanets and brown dwarfs, we might expect to find objects…
The GAIA space observatory was recently approved as Cornerstone 6 of ESA's science program, to be launched no later than mid-2012. It will provide a stereoscopic and kinematic census of about 10^9 stars throughout our Galaxy (and into the…
In astrometric binaries, the presence of a dark, unseen star can be inferred from the gravitational pull it induces on its luminous binary companion. While the orbit of such binaries can be characterized with precise astrometric…