Letter to the Editor

The secondary eclipse of the transiting exoplanet CoRoT-2b ^*

¹ Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland e-mail: roi.alonso@unige.ch
² Observatoire de la Côte d'Azur, Laboratoire Cassiopée, CNRS UMR 6202, BP 4229, 06304 Nice Cedex 4, France
³ Radcliffe Institute for Advanced Studies at Harvard, 8 Garden St. Cambridge MA 02138, USA
⁴ School of Physics and Astronomy, R. and B. Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
⁵ School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
⁶ Laboratoire d'Astrophysique de Marseille, UMR 6110, Technopole de Marseille-Etoile, 13388 Marseille Cedex 13, France
⁷ Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany

Received: 15 May 2009
Accepted: 14 June 2009

Abstract

We present a study of the light curve of the transiting exoplanet CoRoT-2b, aimed at detecting the secondary eclipse and measuring its depth. The data were obtained with the CoRoT satellite during its first run of more than 140 days. After filtering the low frequencies with a pre-whitening technique, we detect a % secondary eclipse centered on the orbital phase . Assuming a black-body emission of the planet, we estimate a surface brightness temperature of  K. We provide the planet's equilibrium temperature and re-distribution factors as a function of the unknown amount of reflected light. The upper limit for the geometric albedo is 0.12. The detected secondary is the shallowest ever found.