Letter to the Editor
V. CoRoT-Exo-4b: stellar and planetary parameters
LAM, UMR 6110, CNRS/Univ. de Provence, 38 rue F. Joliot-Curie, 13388 Marseille, France e-mail: firstname.lastname@example.org
2 School of Physics A28, University of Sydney, Australia
3 OCA, CNRS UMR 6202, BP 4229, 06304 Nice Cedex 4, France
4 Wise Observatory, Tel Aviv University, Tel Aviv 69978, Israel
5 Thüringer Landessternwarte, 07778 Tautenburg, Germany
6 School of Physics, Univ. of Exeter, Exeter EX4 4QL, UK
7 Instituto de Astrofísica de Canarias, 38205 La Laguna, Spain
8 LESIA, CNRS UMR 8109, Obs. de Paris, 92195 Meudon, France
9 Physikalische Institut Univ. Bern, 3012 Bern, Switzerland
10 IAS, Université Paris XI, 91405 Orsay, France
11 IAP, CNRS, Univ. Pierre & Marie Curie, Paris, France
12 Observatório Nacional, Rio de Janeiro, RJ, Brazil
13 IfA University of Vienna, 1180 Vienna, Austria
14 Institute of Planetary Research, DLR, 12489 Berlin, Germany
15 RSSD, ESA/ESTEC, 2200 Noordwijk, The Netherlands
16 Obs. de Genève, Univ. de Genève, 1290 Sauverny, Switzerland
17 IWF, Austrian Academy of Sciences, 8042 Graz, Austria
18 IAG, Université de Liège, Allée du 6 août 17, Liège 1, Belgium
19 RIU, Universität zu Köln, 50931 Köln, Germany
20 ZAA, Technical University Berlin, 10623 Berlin, Germany
21 LUTH, Obs. de Paris, 5 place J. Janssen, 92195 Meudon, France
Accepted: 14 July 2008
Aims. The CoRoT satellite has announced its fourth transiting planet (Aigrain et al. 2008, A&A, 488, L43) with space photometry. We describe and analyse complementary observations of this system performed to establish the planetary nature of the transiting body and to estimate the fundamental parameters of the planet and its parent star.
Methods. We have analysed high precision radial-velocity data, ground-based photometry, and high signal-to-noise ratio spectroscopy.
Results. The parent star CoRoT-Exo-4 (2MASS 06484671-0040219) is a late F-type star of mass of 1.16 and radius of 1.17 . The planet has a circular orbit with a period of 9.20205 d. The planet radius is 1.19 RJup and the mass is 0.72 MJup. It is a gas-giant planet with a “normal” internal structure of mainly H and He. CoRoT-Exo-4b has the second longest period of the known transiting planets. It is an important discovery since it occupies an empty area in the mass-period diagram of transiting exoplanets.
Key words: planetary systems / techniques: photometric / techniques: radial velocities / stars: fundamental parameters
Based on observations obtained with CoRoT, a space project operated by the French Space Agency, CNES, with participation of the Science Programme of ESA, ESTEC/RSSD, Austria, Belgium, Brazil, Germany and Spain; and on observations made with the SOPHIE spectrograph at Observatoire de Haute Provence, France (PNP.07B.MOUT), and the HARPS spectrograph at ESO La Silla Observatory (079.C-0127/F).
© ESO, 2008