CoRoT LRa02_E2_0121: Neptune-size planet candidate turns into a hierarchical triple system with a giant primary
English
Tal-Or, L.[School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel]
Santerne, A.[Laboratoire d'Astrophysique de Marseille, Université de Provence & CNRS, 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]
Bouchy, F.[Observatoire de Haute Provence, CNRS/OAMP, 04870 St Michel l', Observatoire, France; Institut d'Astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie, 98bis Bd Arago, 75014, Paris, France]
Moutou, C.[Laboratoire d'Astrophysique de Marseille, Université de Provence & CNRS, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Alonso, R.[Observatoire de l'Université de Genève, 51 chemin des Maillettes, 1290, Sauverny, Switzerland]
Gandolfi, D.[Research and Scientific Support Department, ESTEC/ESA, Keplerlaan 1, 2200AG, Noordwijk, The Netherlands]
Auvergne, M.[LESIA, Observatoire de Paris, Place Jules Janssen, 92195, Meudon Cedex, France]
Barge, P.[Laboratoire d'Astrophysique de Marseille, Université de Provence & CNRS, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Bonomo, A. S.[Laboratoire d'Astrophysique de Marseille, Université de Provence & CNRS, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Bordé, P.[Institut d'Astrophysique Spatiale, Université Paris XI, 91405, Orsay, France]
Deeg, H.[Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain; Universidad de La Laguna, Dept. de Astrofísica, 38200 La Laguna, Tenerife, Spain]
Jorda, L.[Laboratoire d'Astrophysique de Marseille, Université de Provence & CNRS, 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, Université de Provence & CNRS, 38 rue Frédéric Joliot-Curie, 13388, Marseille Cedex 13, France]
Ollivier, M.[Institut d'Astrophysique Spatiale, Université Paris XI, 91405, Orsay, France]
Pätzold, M.[Rheinisches Institut für Umweltforschung an der Universität zu Köln, Aachener Strasse 209, 50931, Köln, 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 Jules Janssen, 92195, Meudon Cedex, France]
Tsodikovich, Y.[School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel]
[en] This paper presents the case of CoRoT LRa02_E2_0121, which was initially classified as a Neptune-size transiting-planet candidate on a relatively wide orbit of 36.3 days. Follow-up observations were performed with UVES, Sandiford, SOPHIE, and HARPS. These observations revealed a faint companion in the spectra. To find the true nature of the system we derived the radial velocities of the faint companion using TODMOR - a two-dimensional correlation technique, applied to the SOPHIE spectra. Modeling the lightcurve with EBAS we discovered a secondary eclipse with a depth of ~0.07%, indicating a diluted eclipsing binary. Combined MCMC modeling of the lightcurve and the radial velocities suggested that CoRoT LRa02_E2_0121 is a hierarchical triple system with an evolved G-type primary and an A-type:F-type grazing eclipsing binary. Such triple systems are difficult to discover. Based on observations made with the 1.93-m telescope at Observatoire de Haute-Provence (CNRS), France, the 3.6-m telescope at La Silla Observatory (ESO), Chile (program 184.C-0639), the VLT at Paranal Observatory (ESO), Chile (program 083.C-0690), and the 2.1-m Otto Struve telescope at McDonald Observatory, Texas, USA.
[Oxford Astrophyiscs, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH, UK; University of Liège, Allée du 6 août 17, Sart Tilman, Liège 1, Belgium]
