The secondary eclipse of CoRoT-1b^*

¹ Laboratoire d'Astrophysique de Marseille, UMR 6110, Technopole de Marseille-Etoile, 13388 Marseille Cedex 13, France e-mail: roi.alonso@oamp.fr
² Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland
³ School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
⁴ LESIA, CNRS UMR 8109, Observatoire de Paris, 5 place J. Janssen, 92195 Meudon, France
⁵ IAS, UMR 8617 CNRS, bat 121, Universite Paris-Sud, 91405 Orsay, France
⁶ Observatoire de Haute-Provence, 04870 St Michel l'Observatoire, France
⁷ Observatório Nacional, Rio de Janeiro, RJ, Brazil
⁸ Instituto de Astrofísica de Canarias, 38205 La Laguna, Spain
⁹ Institute for Astronomy, University of Vienna, Türkenschanzstrasse 17, 1180 Vienna, Austria
¹⁰ Institute of Planetary Research, DLR, Rutherfordstr. 2, 12489 Berlin, Germany
¹¹ Research and Scientific Support Department, European Space Agency, ESTEC, 2200 Noordwijk, The Netherlands
¹² Observatoire de la Côte d'Azur, Laboratoire Cassiopée, CNRS UMR 6202, BP 4229, 06304 Nice Cedex 4, France
¹³ Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany
¹⁴ Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria
¹⁵ Institut d'Astrophysique et de Géophysique, Université de Liège, Allée du 6 août 17, Sart Tilman, Liège 1, Belgium
¹⁶ School of Physics and Astronomy, R. and B. Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
¹⁷ Rheinisches Institut für Umweltforschung, Universität zu Köln, Abt. Planetenforschung, Aachener Str. 209, 50931 Köln, Germany
¹⁸ Center for Astronomy and Astrophysics, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
¹⁹ LUTH, Observatoire de Paris-Meudon, 5 place J. Janssen, 92195 Meudon, France

Received: 18 March 2009
Accepted: 7 July 2009

Abstract

The transiting planet CoRoT-1b is thought to belong to the pM-class of planets, in which the thermal emission dominates in the optical wavelengths. We present a detection of its secondary eclipse in the CoRoT white channel data, whose response function goes from ~400 to ~1000 nm. We used two different filtering approaches, and several methods to evaluate the significance of a detection of the secondary eclipse. We detect a secondary eclipse centered within 20 min at the expected times for a circular orbit, with a depth of %. The center of the eclipse is translated in a 1-σ upper limit to the planet's eccentricity of . Under the assumption of a zero Bond Albedo and blackbody emission from the planet, it corresponds to a  K. We provide the equilibrium temperatures of the planet as a function of the amount of reflected light. If the planet is in thermal equilibrium with the incident flux from the star, our results imply an inefficient transport mechanism of the flux from the day to the night sides.