The CORALIE survey for southern extrasolar planets

XVII. New and updated long period and massive planets^⋆,⋆⋆

¹ Observatoire astronomique de l’Université de Genève, 51 ch. des Maillettes Sauverny, 1290 Versoix, Switzerland
e-mail: Maxime.Marmier@unige.ch
² Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
³ Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
⁴ Instituto de Astrofísica de Canarias, C/vía Láctea S/N, 38200 La Laguna, Spain
⁵ Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Spain
⁶ Université de Liège, Allée du 6 août 17, Sart Tilman, Liège 1, Belgium
⁷ School of Mathematical Sciences, Monash University, 3800 Victoria, Australia
⁸ Departamento de Física, Universidade Federal do Rio Grande do Norte, 59072-970, Natal, RN., Brazil
⁹ Department of Earth, Atmospheric and Planetary Sciences, Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139, USA
¹⁰ Laboratoire d’astrophysique, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, 1290 Versoix, Switzerland

Received: 21 May 2012
Accepted: 25 November 2012

Abstract

Context. Since 1998, a planet-search program around main sequence stars within 50 pc in the southern hemisphere has been carried out with the CORALIE echelle spectrograph at La Silla Observatory.

Aims. With an observing time span of more than 14 years, the CORALIE survey is now able to unveil Jovian planets on Jupiter’s period domain. This growing period-interval coverage is important for building formation and migration models since observational constraints are still weak for periods beyond the ice line.

Methods. Long-term precise Doppler measurements with the CORALIE echelle spectrograph, together with a few additional observations made with the HARPS spectrograph on the ESO 3.6 m telescope, reveal radial velocity signatures of massive planetary companions on long-period orbits.

Results. In this paper we present seven new planets orbiting HD 27631, HD 98649, HD 106515A, HD 166724, HD 196067, HD 219077, and HD 220689, together with the CORALIE orbital parameters for three already known planets around HD 10647, HD 30562, and HD 86226. The period range of the new planetary companions goes from 2200 to 5500 days and covers a mass domain between 1 and 10.5 M_Jup. Surprisingly, five of them present very high eccentricities above e > 0.57. A pumping scenario by Kozai mechanism may be invoked for HD 106515Ab and HD 196067b, which are both orbiting stars in multiple systems. Since the presence of a third massive body cannot be inferred from the data of HD 98649b, HD 166724b, and HD 219077b, the origin of the eccentricity of these systems remains unknown. Except for HD 10647b, no constraint on the upper mass of the planets is provided by Hipparcos astrometric data. Finally, the hosts of these long period planets show no metallicity excess.