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

Sz. Csizmadia, A. Hatzes, D. Gandolfi, M. Deleuil, F. Bouchy, M. Fridlund, L. Szabados, H. Parviainen, J. Cabrera, S. Aigrain, R. Alonso, J. -M. Almenara, A. Baglin, P. Bordé, A. S. Bonomo, H. J. Deeg, R. F. Díaz, A. Erikson, S. Ferraz-Mello, M. Tadeu dos Santos, E. W. Guenther, T. Guillot, S. Grziwa, G. Hébrard, P. Klagyivik, M. Ollivier, M. Pätzold, H. Rauer, D. Rouan, A. Santerne, J. Schneider, T. Mazeh, G. Wuchterl, S. Carpano, A. Ofir

Abstract
We report the detection of a rare transiting brown dwarf with a mass of 59 MJup and radius of 1.1 RJup 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.

Keywords
brown dwarfs - stars: rotation, eclipses

Astronomy and Astrophysics
Volume 584, Page A13
November 2015

DOI: 10.1051/0004-6361/201526763
ADS Bibliographic code: 2015A%26A...584A..13C