The CORALIE survey for southern extrasolar planets

XVIII. Three new massive planets and two low-mass brown dwarfs at greater than 5 AU separation^★,★★

¹ Département d’astronomie, Université de Genève, 51 ch. des Maillettes, 1290 Versoix, Switzerland
e-mail: emily.rickman@unige.ch
² Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, 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 Institute of Physics, Laboratory of Astrophysics, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, 1290, Versoix, Switzerland
⁵ European Southern Observatory, Alonso de Córdova 3107, Vitacura, Santiago, Chile
⁶ Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA
⁷ Department of Physics, University of Warwick, Coventry CV4 7AL, UK
⁸ Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
⁹ Carnegie Institution for Science, Las Campanas Observatory, Casilla 601, Colina El Pino s/n, La Serena, Chile
¹⁰ Physikalisches Institut, Universität Bern, Gesellschaftsstr. 6, 3012 Bern, Switzerland
¹¹ Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
¹² School of Physics & Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
¹³ Leiden Observatory, Leiden University, Postbus 9513, 2300 RA Leiden, Netherlands

Received: 25 February 2019
Accepted: 2 April 2019

Abstract

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

Aims. With an observing time span of more than 20 yr, the CORALIE survey is able to detect long-term trends in data with masses and separations large enough to select ideal targets for direct imaging. Detecting these giant companion candidates will allow us to start bridging the gap between radial-velocity-detected exoplanets and directly imaged planets and brown dwarfs.

Methods. Long-term precise Doppler measurements with the CORALIE spectrograph reveal radial-velocity signatures of massive planetary companions and brown dwarfs on long-period orbits.

Results. In this paper, we report the discovery of new companions orbiting HD 181234, HD 13724, HD 25015, HD 92987 and HD 50499. We also report updated orbital parameters for HD 50499b, HD 92788b and HD 98649b. In addition, we confirm the recent detection of HD 92788c. The newly reported companions span a period range of 15.6–40.4 yr and a mass domain of 2.93–26.77 M_Jup, the latter of which straddles the nominal boundary between planets and brown dwarfs.

Conclusions. We report the detection of five new companions and updated parameters of four known extrasolar planets. We identify at least some of these companions to be promising candidates for imaging and further characterisation.