Searching for exosolar planets with the COROT space mission

The space mission COROT(to be launched in 2002) will continuously monitor t he flux of a number of stars during 150 days periods with a very high photo metric accuracy. One of its objectives is the detection of extra-solar plan ets by looking for their transits in front of the disk of several tens thou sand stars. COROT accommodates a 25 cm telescope with low straylight, and 4 2048 x 2048 CCDs, 2 of which monitoring 5000 to 12000 stars simultaneously up to m(V) = 16.5. The stability and noise performances should make easy t he detection of Jupiter-like planets and possible the detection of Earth-li ke planets with radius > 1.5R.. Under study is a dispersive system that wil l allow to retrieve some chromatic information : this could be essential to discriminate actual transit events against stellar fluctuations that would mimic a transit and to identify properly the events occurring in binary st ars. The mission, the instrument and the results of simulations are present ed, together with a discussion on the number of expected events : the multi ple ones with a short orbital period signature, or the single or double eve nts identified by their (a)chromatic signature. The later ones may lead to the discovery of planets in the habitable zone. (C) 1999 Elsevier Science L td. All rights reserved.