Institut d'Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17, Bât. B5C, Liège 1, Belgium e-mail: email@example.com
2 Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
3 Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA
4 School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK
5 Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK
6 Laboratoire d'Astrophysique de Marseille (UMR 6110), 38 rue Frédéric Joliot-Curie, 13388 Marseille, France
Accepted: 26 May 2009
We present VLT eclipse photometry for the giant planet CoRoT-1b. We observed a transit in the R-band filter and an occultation in a narrow filter centered on 2.09 μm. Our analysis of this new photometry and published radial velocities, in combination with stellar-evolutionary modeling, leads to a planetary mass and radius of 1.07 MJup and 1.45 RJup, confirming the very low density previously deduced from CoRoT photometry. The large occultation depth that we measure at 2.09 μm (0.278) is consistent with thermal emission and is better reproduced by an atmospheric model with no redistribution of the absorbed stellar flux to the night side of the planet.
Key words: binaries: eclipsing / planetary systems / stars: individual: CoRoT-1 / infrared: stars / techniques: photometric / techniques: radial velocities
Based on data collected with the VLT/FORS2 and VLT/HAWK-I instruments at ESO Paranal Observatory, Chile (programs 080.C-0661(B) and 382.C-0642(A)).
© ESO, 2009