Exoplanet Discoveries with the CoRoT Space Observatory

Abstract

The CoRoT space observatory is a project which is led by the French space agency CNES and leading space research institutes in Austria, Brazil, Belgium, Germany and Spain and also the European Space Agency ESA. CoRoT observed since its launch in December 27, 2006 about 100 000 stars for the exoplanet channel, during 150 days uninterrupted highprecision photometry. Since the The CoRoTteam has several exoplanet candidates which are currently analyzed under its study, we report here the discoveries of nine exoplanets which were observed by CoRoT. Discovered exoplanets such as CoRoT3b populate the brown dwarf desert and close the gap of mea sured physical properties between usual gas giants and very low mass stars. CoRoT discoveries extended the known range of planet masses down to about 4.8 Earthmasses (CoRoT7b) and up to 21 Jupiter masses (CoRoT3b), the radii to about 1.68 × 0.09 R_(Earth) (CoRoT7b) and up to the most inflated hot Jupiter with 1.49 × 0.09 R_(Earth) found so far (CoRoT1b), and the transiting exoplanet with the longest period of 95.274 days (CoRoT9b). Giant exoplanets have been detected at low metallicity, rapidly rotating and active, spotted stars. Two CoRoT planets have host stars with the lowest content of heavy elements known to show a transit hinting towards a different planet hoststarmetallicity relation then the one found by radialvelocity search programs. Finally the properties of the CoRoT7b prove that rocky planets with a density close to Earth exist outside the Solar System. Finally the detec tion of the secondary transit of CoRoT1b at a sensitivity level of 10^(–5) and the very clear detection of the “super Earth” CoRoT7b at 3.5 × 10^(–4) relative flux are promising evidence that the space observatory is being able to detect even smaller exoplanets with the size of the Earth.