CoRoT’s first seven planets: An overview^*

¹ Institute for Astronomy, Türkenschanzstrasse 17, 1180 Vienna, Austria
² LUTH, Observatoire de Paris-Meudon, 5 place J. Jansen, 92195 Meudon, Paris, France
³ Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria
⁴ Laboratoire d’Astrophysique de Marseille, Technopole de Marseille-Etoile, 13388 Marseille Cedex 13, France
⁵ Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany

Abstract

The up to 150 day uninterrupted high-precision photometry of about 100000 stars – provided so far by the exoplanet channel of the CoRoT space telescope – gave a new perspective on the planet population of our galactic neighbourhood. The seven planets with very accurate parameters widen the range of known planet properties in almost any respect. Giant planets have been detected at low metallicity, rapidly rotating and active, spotted stars. CoRoT-3 populated the brown dwarf desert and closed the gap of measured physical properties between standard giant planets and very low mass stars. CoRoT extended the known range of planet masses down-to 5 Earth masses and up to 21 Jupiter masses, the radii to less than 2 Earth radii and up to the most inflated hot Jupiter found so far, and the periods of planets discovered by transits to 9 days. Two CoRoT planets have host stars with the lowest content of heavy elements known to show a transit hinting towards a different planet-host-star-metallicity relation then the one found by radial-velocity search programs. Finally the properties of the CoRoT-7b prove that terrestrial planets with a density close to Earth exist outside the Solar System. The detection of the secondary transit of CoRoT-1 at the 10⁻⁵-level and the very clear detection of the 1.7 Earth radii of CoRoT-7b at 3.5 10⁻⁴ relative flux are promising evidence of CoRoT being able to detect even smaller, Earth sized planets.