Transiting exoplanets from the CoRoT space mission^⋆,⋆⋆

XXVIII. CoRoT-33b, an object in the brown dwarf desert with 2:3 commensurability with its host star

¹ Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, 12489 Berlin, Germany
e-mail: szilard.csizmadia@dlr.de
² Thüringer Landessternwarte, Sternwarte 5, Tautenburg 5, 07778 Tautenburg, Germany
³ Dipartimento di Fisica, Universitá di Torino, via P. Giuria 1, 10125 Torino, Italy
⁴ Landessternwarte Königstuhl, Zentrum für Astronomie der Universität Heidelberg, Königstuhl 12, 69117 Heidelberg, Germany
⁵ Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
⁶ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
⁷ Leiden Observatory, University of Leiden, PO Box 9513, 2300 RA, Leiden, The Netherlands
⁸ Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
⁹ Konkoly Observatory of the Hungarian Academy of Sciences, MTA CSFK, Budapest, Konkoly Thege Miklós út 15-17, Hungary
¹⁰ Sub-department of Astrophysics, Department of Physics, University of Oxford, Oxford, OX1 3RH, UK
¹¹ Department of Physics, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH, UK
¹² Instituto de Astrofísica de Canarias, 38205, La Laguna, Tenerife, Spain
¹³ Universidad de La Laguna, Dept. de Astrofísica, 38206, La Laguna, Tenerife, Spain
¹⁴ LESIA, UMR 8109 CNRS, Observatoire de Paris, UPMC, Université Paris-Diderot, 5 place J. Janssen, 92195 Meudon, France
¹⁵ LAB, UMR 5804, Univ. Bordeaux & CNRS, 33270 Floirac, France
¹⁶ INAF–Osservatorio Astrofisico di Torino Strada Osservatorio, 20 10025 Pino Torinese ( TO), Italy
¹⁷ Observatoire astronomique de l’Université de Genève, 51 ch. des Maillettes, 1290 Versoix, Switzerland
¹⁸ IAG-Universidade de São Paulo, 1226 Sâo Paulo, Brasil
¹⁹ Université de Nice-Sophia Antipolis, CNRS UMR 6202, Observatoire de la Côte d’Azur, BP 4229, 06304 Nice Cedex 4, France
²⁰ Rheinisches Institut für Umweltforschung an der Universität zu Köln, 50931 Aachener Strasse 209, Germany
²¹ Institut d’Astrophysique de Paris, UMR 7095 CNRS, Université Pierre & Marie Curie, 98bis boulevard Arago, 75014 Paris, France
²² Institut d’Astrophysique Spatiale, Université Paris XI, 91405 Orsay, France
²³ Center for Astronomy and Astrophysics, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
²⁴ Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
²⁵ LUTH, Observatoire de Paris, UMR 8102 CNRS, Université Paris Diderot, 5 place Jules Janssen, 92195 Meudon, France
²⁶ School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, 39040 Tel Aviv University, Tel Aviv, Israel
²⁷ Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany
²⁸ Department of Earth and Planetary Sciences, Weizmann Institute of Science, 234 Herzl St., 76100 Rehovot, Israel

Received: 16 June 2015
Accepted: 28 July 2015

Abstract

We report the detection of a rare transiting brown dwarf with a mass of 59 M_Jup and radius of 1.1 R_Jup around the metal-rich, [Fe/H] = +0.44, G9V star CoRoT-33. The orbit is eccentric (e = 0.07) with a period of 5.82 d. The companion, CoRoT-33b, is thus a new member in the so-called brown dwarf desert. The orbital period is within 3% to a 3:2 resonance with the rotational period of the star. CoRoT-33b may be an important test case for tidal evolution studies. The true frequency of brown dwarfs close to their host stars (P< 10 d) is estimated to be approximately 0.2% which is about six times smaller than the frequency of hot Jupiters in the same period range. We suspect that the frequency of brown dwarfs declines faster with decreasing period than that of giant planets.