Observatoire de Paris
Les ExoplanètesCoRoTCoursOutilsBase de données
<-   The detected exoplanets   ->
With the CoRoT satellite, we try to discover extrasolar planets with sizes in the order of the size of terrestrial planets in our solar system.
Crédit : NASA / ASM

The first exoplanet was discoverd in 1995 at the Haute-Provence Observatory.

From 1995 to 2004, we found more than 120 planets around more than 100 planetary systems.

These systems are really surprising :

  • The planets are very massive (Jupiter's mass or more). However, they are 10 to 100 times closer to their stars than Jupiter is to the Sun. Their rotation periods around their stars are therefore 3 to 1000 times shorter.
  • Some planetary orbits in these systems are very elongated ellipses, whereas in the solar system, the orbits are circles.

In the nineties, a systematic follow-up of the radial velocity variations of bright stars similar to the Sun, aimed at discovering double stars, revealed the existence of exoplanets, objects with very low mass in orbit around a star.

It is the star 51 Pegasi which showed the first exoplanet in 1995, thanks to observations made at the Haute-Provence Observatory, by a French-Swiss team supervised by Michel Mayor.