Transiting exoplanets from the CoRoT space mission. XVIII. CoRoT-18b: a massive hot Jupiter on a prograde, nearly aligned orbit
English
Hébrard, G.[Institut d'Astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie, 98bis boulevard Arago, 75014, Paris, France ; Observatoire de Haute-Provence, CNRS/OAMP, 04870, Saint-Michel-l'Observatoire, France]
Evans, T. M.[Department of Physics, Denys Wilkinson Building Keble Road, Oxford, OX1 3RH, UK]
Alonso, R.[Observatoire de l'Université de Genève, 51 chemin des Maillettes, 1290, Sauverny, Switzerland]
Fridlund, M.[Research and Scientific Support Department, European Space Agency, Keplerlaan1, 2200AG, Noordwijk, The Netherlands]
Ofir, A.[School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel]
Aigrain, S.[Department of Physics, Denys Wilkinson Building Keble Road, Oxford, OX1 3RH, UK]
Guillot, T.[Observatoire de la Côte d'Azur, Laboratoire Cassiopée, BP 4229, 06304, Nice Cedex 4, France]
Almenara, J. M.[Laboratoire d'Astrophysique de Marseille, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France; Instituto de Astrofísica de Canarias, and Universidad de La Laguna, Dept. de Astrofísica, 38205, La Laguna, Tenerife, Spain]
Auvergne, M.[LESIA, Observatoire de Paris, Place J. Janssen, 92195, Meudon Cedex, France]
Baglin, A.[LESIA, Observatoire de Paris, Place J. Janssen, 92195, Meudon Cedex, France]
Barge, P.[Laboratoire d'Astrophysique de Marseille, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Bonomo, A. S.[Laboratoire d'Astrophysique de Marseille, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Bordé, P.[Institut d'Astrophysique Spatiale, Université Paris XI, 91405, Orsay, France]
Bouchy, F.[Institut d'Astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie, 98bis boulevard Arago, 75014, Paris, France; Observatoire de Haute-Provence, CNRS/OAMP, 04870, Saint-Michel-l'Observatoire, France]
Cabrera, J.[Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, 12489, Berlin, Germany]
Carone, L.[Rheinisches Institut für Umweltforschung an der Universität zu Köln, Aachener Strasse 209, 50931, Germany]
Carpano, S.[Research and Scientific Support Department, European Space Agency, Keplerlaan1, 2200AG, Noordwijk, The Netherlands]
Cavarroc, C.[Institut d'Astrophysique Spatiale, Université Paris XI, 91405, Orsay, France]
Csizmadia, Szilard[Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, 12489, Berlin, Germany]
Deeg, H. J.[Instituto de Astrofísica de Canarias, and Universidad de La Laguna, Dept. de Astrofísica, 38205, La Laguna, Tenerife, Spain]
Deleuil, M.[Laboratoire d'Astrophysique de Marseille, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Díaz, R. F.[Institut d'Astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie, 98bis boulevard Arago, 75014, Paris, France; Observatoire de Haute-Provence, CNRS/OAMP, 04870, Saint-Michel-l'Observatoire, France]
Dvorak, R.[University of Vienna, Institute of Astronomy, Türkenschanzstr. 17, 1180, Vienna, Austria]
Erikson, A.[Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, 12489, Berlin, Germany]
Havel, M.[Observatoire de la Côte d'Azur, Laboratoire Cassiopée, BP 4229, 06304, Nice Cedex 4, France]
Jorda, L.[Laboratoire d'Astrophysique de Marseille, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Lammer, H.[Space Research Institute, Austrian Academy of Science, Schmiedlstr. 6, 8042, Graz, Austria]
Léger, A.[Institut d'Astrophysique Spatiale, Université Paris XI, 91405, Orsay, France]
Llebaria, A.[Laboratoire d'Astrophysique de Marseille, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Mazeh, T.[School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel]
Moutou, C.[Laboratoire d'Astrophysique de Marseille, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Ollivier, M.[Institut d'Astrophysique Spatiale, Université Paris XI, 91405, Orsay, France]
Parviainen, H.[Instituto de Astrofísica de Canarias, and Universidad de La Laguna, Dept. de Astrofísica, 38205, La Laguna, Tenerife, Spain]
Pätzold, M.[Rheinisches Institut für Umweltforschung an der Universität zu Köln, Aachener Strasse 209, 50931, Germany]
Queloz, D.[Observatoire de l'Université de Genève, 51 chemin des Maillettes, 1290, Sauverny, Switzerland]
Rauer, H.[Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, 12489, Berlin, Germany; Center for Astronomy and Astrophysics, TU Berlin, Hardenbergstr. 36, 10623, Berlin, Germany]
Rouan, D.[LESIA, Observatoire de Paris, Place J. Janssen, 92195, Meudon Cedex, France]
Santerne, A.[Laboratoire d'Astrophysique de Marseille, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Schneider, J.[LUTH, Observatoire de Paris, CNRS, Université Paris Diderot, 5 place Jules Janssen, 92195, Meudon, France]
Tingley, B.[Instituto de Astrofísica de Canarias, and Universidad de La Laguna, Dept. de Astrofísica, 38205, La Laguna, Tenerife, Spain]
[en] We report the detection of CoRoT-18b, a massive hot Jupiter transiting in front of its host star with a period of 1.9000693 ± 0.0000028 days. This planet was discovered thanks to photometric data secured with the CoRoT satellite combined with spectroscopic and photometric ground-based follow-up observations. The planet has a mass M[SUB]p[/SUB] = 3.47 ± 0.38 M[SUB]Jup[/SUB], a radius R[SUB]p[/SUB] = 1.31 ± 0.18 R[SUB]Jup[/SUB], and a density ρ[SUB]p[/SUB] = 2.2 ± 0.8 g cm[SUP]-3[/SUP]. It orbits a G9V star with a mass M[SUB]⋆[/SUB] = 0.95 ± 0.15 M[SUB]&sun;[/SUB], a radius R[SUB]⋆[/SUB] = 1.00 ± 0.13 R[SUB]&sun;[/SUB], and arotation period P[SUB]rot[/SUB] = 5.4 ± 0.4 days. The age of the system remains uncertain, with stellar evolution models pointing either to a few tens Ma or several Ga, while gyrochronology and lithium abundance point towards ages of a few hundred Ma. This mismatch potentially points to a problem in our understanding of the evolution of young stars, with possibly significant implications for stellar physics and the interpretation of inferred sizes of exoplanets around young stars. We detected the Rossiter-McLaughlin anomaly in the CoRoT-18 system thanks to the spectroscopic observation of a transit. We measured the obliquity ψ = 20° ± 20° (sky-projected value λ = -10° ± 20°), indicating that the planet orbits in the same way as the star is rotating and that this prograde orbit is nearly aligned with the stellar equator. The CoRoT space mission, launched on 2006 December 27, has been developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany and Spain.Table 2 is available in electronic form at <A href="http://www.aanda.org">http://www.aanda.org</A>
[University of Liège, Allée du 6 août 17, Sart Tilman, Liège 1, Belgium]
