Related papers: The astrometric core solution for the Gaia mission…
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…
Gaia measures the five astrometric parameters for stars in the Milky Way, but only four of them (positions and proper motion, but not parallax) are well measured beyond a few kpc from the Sun. Modern spectroscopic surveys such as APOGEE…
The Gaia payload ensures maximum passive stability using a single material, SiC, for most of its elements. Dedicated metrology instruments are, however, required to carry out two functions: monitoring the basic angle and refocusing the…
Using data from Gaia DR3, we construct a sample of 14,791 gravitationally bound wide pairs in which one of the components is an unresolved binary with an astrometric orbital or acceleration solution. These systems are hierarchical triples,…
Europe's Gaia spacecraft will soon embark on its five-year mission to measure the absolute parallaxes of the complete sample of 1,000 million objects down to 20 mag. It is expected that thousands of nearby brown dwarfs will have their…
The Gaia astrometric mission - the Hipparcos successor - is described in some detail, with its three instruments: the two (spectro)photometers (BP and RP) covering the range 330-1050 nm, the white light (G-band) imager dedicated to…
The ESA Gaia space astrometry mission will perform an all-sky survey of stellar objects complete in the nominal magnitude range G = [6.0 - 20.0]. The stars with G lower than 6.0, i.e. those visible to the unaided human eye, would thus not…
The GBOT group is in charge of the Ground Based Optical Tracking of the Gaia satellite. In concrete terms, since the launch of Gaia, our task is to take every night, using ground based medium-class telescopes, short sequences of $10$ or…
The ESA Gaia mission uses two telescopes to create the most ambitious survey of the Galaxy. The angle between them must be known with exquisite precision and accuracy. An interferometer: the Basic Angle Monitoring system measures its…
(Abridged) Gaia aims to make a 3-dimensional map of 1,000 million stars in our Milky Way to unravel its kinematical, dynamical, and chemical structure and evolution. Gaia's on-board detection software discriminates stars from spurious…
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…
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…
GAIA is a short-listed candidate for the ESA Cornerstone mission C5, meeting the ESA Survey Committee requirement for an observatory mission, dedicated to astrometry, providing 10 micro-arcsecond accuracy at 15th magnitude. The GAIA mission…
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…
In its all-sky survey, Gaia will monitor astrometrically and photometrically millions of main-sequence stars with sufficient sensitivity to brown dwarf companions within a few AUs from their host stars and to transiting brown dwarfs on very…
The Gaia spacecraft of the European Space Agency (ESA) has been securing observations of solar system objects (SSOs) since the beginning of its operations. Gaia Data Release 2 (DR2) contains the observations of a selected sample of 14,099…
Direct imaging searches for exoplanets around stars detect many spurious candidates that are in fact background field stars. To help distinguish these from genuine companions, multi-epoch astrometry can be used to identify a common proper…
The Gaia mission is described, focussing on those technical aspects that are necessary to understand the details of its external (absolute) flux calibration. On board of Gaia there will be two (spectro)photometers, the blue one (BP) and the…
Scope of this contribution is twofold. First, it describes the potential of the global astrometry mission Gaia for detecting and measuring planetary systems based on detailed double-blind mode simulations and on the most recent predictions…
We use the Gaia DR2 catalog to improve the astrometric accuracy of about 1.7 billion objects in Pan-STARRS1 Data Release 2 (PS1 DR2). We also obtain proper motions for these PS1 objects. The cross match between Gaia and PS1 reveals…