EDP Sciences
Free Access
Volume 474, Number 2, November I 2007
Page(s) 647 - 651
Section Planets and planetary systems
DOI https://doi.org/10.1051/0004-6361:20078129

A&A 474, 647-651 (2007)
DOI: 10.1051/0004-6361:20078129

The HARPS search for southern extra-solar planets

XII. A giant planet orbiting the metal-poor star HD 171028
N. C. Santos1, 2, M. Mayor2, F. Bouchy3, F. Pepe2, D. Queloz2, and S. Udry2

1  Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
    e-mail: nuno@astro.up.pt
2  Observatoire de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland
3  Institut d'Astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie, 98bis Bd Arago, 75014 Paris, France

(Received 21 June 2007 / Accepted 7 August 2007)

In this paper we present the detection of a 1.8  $M_{{\rm Jup}}$ planet in a 538-day period trajectory orbiting the metal-poor star HD 171028 ([Fe/H] = -0.49). This planet is the first to be discovered in the context of a HARPS program searching for planets around metal-poor stars. Interestingly, HD 171028 is one of the least metal-poor stars in the sample. This discovery is placed in the context of the models of planet formation and evolution.

Key words: stars: planetary systems -- planetary systems: formation -- techniques: radial velocity -- stars: abundances

© ESO 2007