Résumé / Abstract Seminaire_IAP
« Gaia explores the Milky Way »

François Mignard
Obs. Côte d'Azur (OCA) (Nice, France)

On the 14th September 2016 the European Space Agency and the European consortium DPAC have jointly released the first results of Gaia, precisely 1000 days after the launch. With one billions stars catalogued with accurate positions, the Gaia scientists have produced the best ever map of the sky. In addition a smaller astrometric catalogue with 2 million stars includes also their distances and annual motion on the plane of the sky. A small set of variable stars with light-curves and a reference system based on the extragalactic sources of the ICRF positioned for the first time in the visible are parts of this release. Gaia is basically a big camera fitted with 106 CCD detectors able to detect in full autonomy more than 50 million sources per day. Orbiting the Sun-Earth L2 at 1.5 million km from the Earth, the satellite spins regularly with a 6h-period allowing to scan the whole sky every six months, so as to sample the parallactic displacement of every detectable star. A photometer and a spectrometer complete the on-board instrumentation and provide additional kinematical and physical data on the sources. Every day 40GB of raw data is sent to the ground and processed by a consortium of European institutes. During the seminar I will summarise the main scientific objectives of the mission and the technical means implemented to achieve the goals and get a the mission completion positions, distances and proper motions of more than one billion sources. The main results of the Gaia DR1 will be presented and I will describe the current status of the program and detail the content of the second release scheduled in Spring 2018.
vendredi 31 mars 2017 - 11:00
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage