The SOPHIE search for northern extrasolar planets^★,★★

XIII. Two planets around M-dwarfs Gl617A and Gl96

¹ Laboratoire d’Astrophysique de Marseille, UMR 7326, CNRS, Aix-Marseille Université, 13388 Marseille Cedex 13, France
e-mail: melissa.hobson@lam.fr
² Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
³ Instituto de Astronomía y Física del Espacio (IAFE), CONICET – Universidad de Buenos Aires, Buenos Aires, Argentina
⁴ CNRS, IPAG, Université Grenoble Alpes, 38000 Grenoble, France
⁵ Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción, Chile
⁶ Observatoire Astronomique de lUniversité de Gen, 51 Chemin des Maillettes, 1290 Versoix, Switzerland
⁷ ASD/IMCCE, CNRS-UMR8028, Observatoire de Paris, PSL, UPMC, 77 Avenue Denfert-Rochereau, 75014 Paris, France
⁸ Observatoire de Haute-Provence, CNRS, Institut Pythéas UMS 3470, Aix-Marseille Université, 04870 Saint-Michel-lObservatoire, France
⁹ Institut dAstrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie, 98bis Boulevard Arago, 75014 Paris, France
¹⁰ Instituto de Astrofísica e Ciências do Espaço, CAUP, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
¹¹ Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
¹² Canada-France-Hawaii Telescope Corporation, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743, USA
¹³ Leiden Observatory, Leiden University, Postbus 9513, 2300 RA Leiden, The Netherlands

Received: 30 January 2018
Accepted: 27 June 2018

Abstract

We report the detection of two exoplanets and a further tentative candidate around the M-dwarf stars Gl96 and Gl617A, based on radial velocity measurements obtained with the SOPHIE spectrograph at the Observatoire de Haute-Provence. Both stars were observed in the context of the SOPHIE exoplanet consortium’s dedicated M-dwarf subprogramme, which aims to detect exoplanets around nearby M-dwarf stars through a systematic survey. For Gl96 we present the discovery of a new exoplanet at 73.9 d with a minimum mass of 19.66 earth masses. Gl96 b has an eccentricity of 0.44, placing it among the most eccentric planets orbiting M stars. For Gl617A we independently confirm a recently reported exoplanet at 86.7 d with a minimum mass of 31.29 earth masses. Both Gl96 b and Gl617A b are potentially within the habitable zone, although the high eccentricity of Gl96 b may take it too close to the star at periapsis.