Transiting exoplanets from the CoRoT space mission

XIV. CoRoT-11b: a transiting massive “hot-Jupiter” in a prograde orbit around a rapidly rotating F-type star^⋆

¹ Thüringer Landessternwarte, Sternwarte 5, Tautenburg, 07778 Tautenburg, Germany
e-mail: davide.gandolfi@esa.int
² Research and Scientific Support Department, ESTEC/ESA, PO Box 299, 2200 AG Noordwijk, The Netherlands
³ Institut d’Astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie, 98bis boulevard Arago, 75014 Paris, France
⁴ Observatoire de l’Université de Genève, 51 chemin des Maillettes, 1290 Sauverny, Switzerland
⁵ Laboratoire d’Astrophysique de Marseille, 38 rue Frédéric Joliot-Curie, 13388 Marseille Cedex 13, France
⁶ McDonald Observatory, University of Texas at Austin, Austin, TX 78712, USA
⁷ Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, 12489 Berlin, Germany
⁸ Université de Nice-Sophia Antipolis, CNRS UMR 6202, Observatoire de la Côte d’Azur, BP 4229, 06304 Nice Cedex 4, France
⁹ Oxford Astrophyiscs, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK
¹⁰ LESIA, Observatoire de Paris, Place Jules Janssen, 92195 Meudon Cedex, France
¹¹ Institut d’Astrophysique Spatiale, Université Paris XI, 91405 Orsay, France
¹² Observatoire de Haute Provence, 04670 Saint Michel l’ Observatoire, France
¹³ LUTH, Observatoire de Paris, CNRS, Université Paris Diderot, 5 place Jules Janssen, 92195 Meudon, France
¹⁴ Rheinisches Institut für Umweltforschung an der Universität zu Köln, Aachener Strasse 209, 50931 Köln, Germany
¹⁵ Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
¹⁶ University of Vienna, Institute of Astronomy, Türkenschanzstr. 17, 1180 Vienna, Austria
¹⁷ IAG, University of São Paulo, Brasil
¹⁸ University of Liège, Allée du 6 août 17, Sart Tilman, Liège 1, Belgium
¹⁹ European Southern Observatory, Alonso de Crdova 3107, Casilla 19001, Santiago de Chile, Chile
²⁰ Space Research Institute, Austrian Academy of Science, Schmiedlstr. 6, 8042 Graz, Austria
²¹ School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
²² Center for Astronomy and Astrophysics, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
²³ Dpto. de Astrofísica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain
²⁴ Laboratoire d’Astronomie de Lille, Université de Lille 1, 1 impasse de l’Observatoire, 59000 Lille, France
²⁵ Institut de Mécanique Céleste et de Calcul des Ephémérides, UMR 8028 du CNRS, 77 avenue Denfert-Rochereau, 75014 Paris, France

Received: 2 June 2010
Accepted: 30 August 2010

Abstract

The CoRoT exoplanet science team announces the discovery of CoRoT-11b, a fairly massive hot-Jupiter transiting a V = 12.9 mag F6 dwarf star (M^∗ = 1.27 ± 0.05 M_⊙, R^∗ = 1.37 ± 0.03 R_⊙, T_eff = 6440 ± 120 K), with an orbital period of P = 2.994329 ± 0.000011 days and semi-major axis a = 0.0436 ± 0.005 AU. The detection of part of the radial velocity anomaly caused by the Rossiter-McLaughlin effect shows that the transit-like events detected by CoRoT are caused by a planet-sized transiting object in a prograde orbit. The relatively high projected rotational velocity of the star (vsini _⋆  = 40 ± 5 km s^-1) places CoRoT-11 among the most rapidly rotating planet host stars discovered so far. With a planetary mass of M_p  = 2.33 ± 0.34 M_Jup and radius R_p  = 1.43 ± 0.03 R_Jup, the resulting mean density of CoRoT-11b (ρ_p = 0.99 ± 0.15 g/cm³) can be explained with a model for an inflated hydrogen-planet with a solar composition and a high level of energy dissipation in its interior.