The SOPHIE search for northern extrasolar planets

VI. Three new hot Jupiters in multi-planet extrasolar systems ^{⋆,⋆⋆,⋆⋆⋆}

¹ Aix Marseille University, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille Cedex 13, France
e-mail: Claire.Moutou@oamp.fr
² Institut d’Astrophysique de Paris, UMR 7095 CNRS, Université Pierre & Marie Curie, 98bis boulevard Arago, 75014 Paris, France
³ Observatoire de Haute-Provence, CNRS & OAMP, 04870, Saint-Michel l’Observatoire, France
⁴ Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
⁵ Centro de Astrofísica, Universidade do Porto, rua das Estrelas, 4150-762 Porto, Portugal
⁶ UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG) UMR 5274, 38041 Grenoble, France
⁷ Atalaia group, Crow Observatory-Portalegre, Portugal
⁸ Centre d’Astronomie, Plateau du Moulin à Vent, 04870 Saint-Michel-l’Observatoire, France
⁹ Oversky, 47 Allée des Palanques, 33127 Saint Jean d’Illac, France
¹⁰ Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal

Received: 16 June 2013
Accepted: 9 October 2013

Abstract

We present high-precision radial-velocity measurements of three solar-type stars: HD 13908, HD 159243, and HIP 91258. The observations were made with the SOPHIE spectrograph at the 1.93 m telescope of the Observatoire de Haute-Provence (France). They show that these three bright stars host exoplanetary systems composed of at least two companions. HD 13908 b is a planet with a minimum mass of 0.865 ± 0.035M_Jup   on a circular orbit with a period of 19.382 ± 0.006 days. There is an outer massive companion in the system with a period of 931 ± 17 days, e = 0.12 ± 0.02, and a minimum mass of 5.13 ± 0.25M_Jup . The star HD 159243  also has two detected companions with respective masses, periods, and eccentricities of M_p= 1.13 ± 0.05 and 1.9 ± 0.13M_Jup , P = 12.620 ± 0.004 and 248.4 ± 4.9 days, and e = 0.02 ± 0.02 and 0.075 ± 0.05. Finally, the star HIP 91258  has a planetary companion with a minimum mass of 1.068 ± 0.038M_Jup , an orbital period of 5.0505 ± 0.0015 days, and a quadratic trend indicating an outer planetary or stellar companion that is as yet uncharacterized. The planet-hosting stars HD 13908, HD 159243, and HIP 91258 are main-sequence stars of spectral types F8V, G0V, and G5V, respectively, with moderate activity levels. HIP 91258  is slightly over-metallic, while the other two stars have solar-like metallicity. The three systems are discussed in the frame of formation and dynamical evolution models of systems composed of several giant planets.