Scientific Rationale

The Symposium "Gaia: at the frontiers of astrometry” will be the closing conference of the European network ELSA (European Leadership in Space Astrometry), a Marie Curie research training network supported by the European Community’s Sixth Framework Programme (FP6). The network started on 1st October 2006 for four years. It is a coordinated action between 14 European institutes involved in the preparation of the European Space Agency mission Gaia. The objectives of this network are the development of theoretical tools and analysis methods for various aspects of the Gaia mission and the transfer of the European expertise in space astrometry acquired with Hipparcos to the new generation of scientists.

Gaia is an ambitious astronomy project selected as one of the cornerstones of the ESA Science Program in October 2000, confirmed by the program committee of ESA in the revaluation of its scientific program in May 2002 and currently in Phase C / D for a launch planned for 2012. Conceived in the wake of the success of the Hipparcos satellite, the first space astrometry mission launched by ESA in 1989, Gaia will measure, on the whole sky, positions, distances, motions and physical properties of more than one billion objects with unparalleled accuracy. By combining the power of discovery of a repeated systematic observation of the sky and the extreme accuracy and homogeneity of its observations, Gaia will determine, without bias, the spatial structure, kinematics and the history of our Galaxy. Gaia will also measure and identify a large number of small bodies in the solar system (asteroids, comets, satellites), extra-solar planets, quasars and compact galaxies, and will make a major contribution to fundamental physics.

Through the ELSA network ten PhD students (ESR = Early Stage Researchers) and five post-docs (ER = Experienced Researchers) have been recruited to work on different aspects of Gaia: data analysis (algorithms, numerical analysis, software engineering), modelling of the instrument, preparation of the scientific exploitation. These activities are conducted in complement to and in close interaction with the Gaia Data Processing and Analysis Consortium (DPAC).

The objectives of the Symposium "Gaia: at the frontiers of astrometry” are to present the results obtained in the framework of this European network and to review the progress of the mission, and of the preparation of the data analysis and of the scientific data exploitation. The Symposium will also be an opportunity to present other aspects of the preparatory work for the scientific exploitation of the Gaia data, not covered within the network, both in terms of theory, modelling and ground-based observations. Finally, Gaia will be put in the 2015 context, and progress on parallel or connected topics will be presented: progress on other astrometric satellites, performance of light detectors in astronomy, processing of massive data sets, especially in astronomy, real-time classification of transients, access to massive data sets, and prospects for ground-based observations in complement to astrometry.