Gaia

Gaia is an ambitious ESA cornerstone mission that will be launched in 2013. The mission will measure the positions, parallaxes, and proper motions of more than 1 billion stars with unprecedented precision. In addition it will provide time series of brightness of all these objects, and the radial velocities and spectra of 100 million stars. During 5 years, the mission will collect a staggering 20000 DVDs of raw data, which will revolutionize our view on the Milky Way. 

 

Gaia will be put in an orbit around the Sun in the Lagrange point L2, and will communicate about 8h per day with the ground-stations on Earth. To achieve the ambitious measurement precision, the requirements on the mechanical and thermal stability of the instruments are extremely stringent. The torus on which the instruments are mounted, for example, will consist entirely of SiC, a very stable ceramic material. Gaia's camera will consist of no less than 106 CCDs, with a total surface of about 93 cm by 42 cm, and a breathtaking 1 billion pixels. 

 

Gaia will for the first time provide a 3D map of a significant part of the Milky Way. With the data provided by the mission, astronomers will be able to study the interaction of the disc and the halo. By computing the motion of the stars backwards in time, it will be possible to make a historical reconstruction of how our Milky Way evolved in time. Gaia will provide insights in how open clusters interact, which parts of our Galaxy are metal rich or metal poor. It will detect hundred thousands of new planetoids, not only in the main belt, but also Trojans and NEAs. The mission will test general relativity, and provide a new international cosmic reference frame. Because Gaia will observe each part of the sky many times during its lifetime, the data will also contain valuable information on time varying phenomena. Many new novae, supernovae, gravitational lenses, and eclipsing binaries are expected. Hundred thousands of new variables stars like RR Lyrae, Cepheids, Mira, delta Scuti stars, etc. will be detected.

 

The scientific data reduction for the Gaia mission is being prepared by the pan-European Data Processing and Analysis Consortium (DPAC). Within this consortium, the IvS is responsible for the specification, the design, the development, and the verification of the software that will take care of the statistical classification of stellar variability, the software that deals with the time series modelling of variable stars, and the software that will process the time series of non-radial main-sequence pulsators. In addition, the IvS actively contributes to the frequency analysis software, and the statistical unsupervised classification software.