26.12.06

Corot launch

Corot astronomy mission. Launch is scheduled 27.12.2006 Paris time 15:23 from Baikonur.

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"By its high photometric performances and its observing runs covering five months without interruption, the COROT experiment aims to be a pioneer mission in the discovery of telluric extrasolar planets, bodies with properties comparable to those of the rocky planets of the solar system."
"Exploring beyond our solar system and probing the heavens for new worlds, possibly Earth's twin, is one of the great scientific quests of the 21st century. CNESMAG recently devoted a special feature to exoplanets to mark the launch of the COROT satellite t."
COROT has two scientific objectives The purpose of stellar seismology is to analyse the vibration modes of the stars which, submitted to forces of gravity, pressure and Coriolis, behave as oscillators with many specific modes. The eigen frequency (between 1 minute and 3 hours), the amplitude (a few ppm in Fourier space) and the lifetime (a few days) of these modes make it possible to determine some important parameters of stellar physics, such as the size and the composition of the core, the limits between radiative and convective zones, or the internal profile of rotation. These oscillating modes, which generate variations of luminosity at the surface of the star, are the only information, with neutrinos, coming from the depth of the stars. Acquired and collected on stars with different mass, age and chemical composition, the Corot light curves will bring a significant amount of data of a new kind about stellar evolution.
A hundred of stars, with magnitude between 6 and 9, will be studied.
The search for exoplanets (telluric)

The method used is the method of the "planetary transits" which consists in detecting a planet by the small periodic drop of brightness on the disc of the star it orbits around. This photometric method, complementary to the radial velocities, has the interest to unveil both orbit period and size (radius) of the planets detected. According to existence hypotheses, the Corot mission should discover, in addition to a large number of giants (hot Jupiters), a few tens of rocky planets (exoEarths). Potential rings or satellites could also be detected around giant extrasolar planets. The chromatric analysis of the Corot light curves, thanks to a dispersion device (prism) mounted in front of the exoplanet channel CCDs, will make it possible to precise the different families of detected events (transits, stellar activity, eclipsing binaries...).
More than 120 000 stars, with magnitude between 12 and 15.5, will be surveyed.