Related papers: Gaia astrometric science performance - post-launch…
The scientific community needs to be prepared to analyse the data from Gaia, one of the most ambitious ESA space missions, to be launched in 2012. The purpose of this paper is to provide data and tools in order to predict in advance how…
We review the mathematical models available for relativistic astrometry, discussing the different approaches and their accuracies in the context of the modern experiments from space like Gaia and GAME, and we show how these models can be…
Determination of absolute parallaxes by means of a scanning astrometric satellite such as Hipparcos or Gaia relies on the short-term stability of the so-called basic angle between the two viewing directions. Uncalibrated variations of the…
The Gaia satellite was selected as a cornerstone mission of the European Space Agency (ESA) in October 2000 and confirmed in 2002 with a current target launch date of 2011. The Gaia mission will gather on the same observational principles…
The Gaia satellite will observe about one billion stars and other point-like sources. The astrometric core solution will determine the astrometric parameters (position, parallax, and proper motion) for a subset of these sources, using a…
Gaia is a satellite mission of the ESA, aiming at absolute astrometric measurements of about one billion stars (all stars down to 20th magnitude, with unprecedented accuracy. Additionally, magnitudes and colors will be obtained for all…
Astrometric surveys such as Gaia and LSST will measure parallaxes for hundreds of millions of stars. Yet they will not measure a single distance. Rather, a distance must be estimated from a parallax. In this didactic article, I show that…
Context. This paper presents an overview of the photometric data that are part of the first Gaia data release. Aims. The principles of the processing and the main characteristics of the Gaia photometric data are presented. Methods. The…
We present a comparison of Gaia Data Release 1 (DR1) parallaxes with photometric parallaxes for a sample of 212 Galactic Cepheids at a median distance of 2~kpc, and explore their implications on the distance scale and the local value of the…
The final astrometric data from the Gaia mission will transform our view of the stellar content of the Galaxy, particularly when complemented with spectroscopic surveys providing stellar parameters, line-of-sight kinematics and elemental…
The Gaia mission has been designed to perform absolute astrometric measurements with unprecedented accuracy; the end-of-mission parallax standard error is required to be 30 micro-arcseconds for a G2V type star of magnitude 15. These…
We compared positions of the Gaia first data release (DR1) secondary data set at its faint limit with CCD positions of stars in 20 fields observed with the VLT/FORS2 camera. The FORS2 position uncertainties are smaller than one…
Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using…
Access to microarcsecond astrometry is now routine in the radio, infrared, and optical domains. In particular the publication of the second data release from the Gaia mission made it possible for every astronomer to work with easily…
Launch of the Gaia space observatory started a new era in astrometry when the accuracy of star coordinates increased by thousands of times. Significant improvement of accuracy was also expected for the coordinates of the Solar system…
In May 2013, I responded with the present paper to ESA's call for White Papers for the definition of Large missions. This was half a year before the launch of ESA's large astrometry mission Gaia. The present proposal for a Gaia successor…
We use 612 single stars with previously published trigonometric parallaxes placing them within 25 pc to evaluate parallaxes released in Gaia's first data release (DR1). We find that the Gaia parallaxes are, on average, $0.24 \pm 0.02$ mas…
ESA recently called for new "Science Ideas" to be investigated in terms of feasibility and technological developments -- for technologies not yet sufficiently mature. These ideas may in the future become candidates for M or L class missions…
The European Gaia astrometry mission is due for launch in 2011. Gaia will rely on the proven principles of ESA's Hipparcos mission to create an all-sky survey of about one billion stars throughout our Galaxy and beyond, by observing all…
Gaia is an astrometric mission that will be launched in spring 2013. There are many scientific outcomes from this mission and as far as our Solar System is concerned, the satellite will be able to map thousands of main belt asteroids (MBAs)…