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Issue A&A Volume 426, Number 1, October IV 2004 Page(s) L19 - L23 Section Letters DOI 10.1051/0004-6361:200400076

A&A 426, L19-L23 (2004)
DOI: 10.1051/0004-6361:200400076

Letter

The HARPS survey for southern extra-solar planets

II. A 14 Earth-masses exoplanet around Arae

N. C. Santos^{1, 2}, F. Bouchy³, M. Mayor², F. Pepe², D. Queloz², S. Udry², C. Lovis², M. Bazot⁴, W. Benz⁵, J.-L. Bertaux⁶, G. Lo Curto⁷, X. Delfosse⁸, C. Mordasini⁵, D. Naef^{7, 2}, J.-P. Sivan³ and S. Vauclair<sup>4

1</sup>  Centro de Astronomia e Astrofísica da Universidade de Lisboa, Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal
    e-mail: nuno.santos@oal.ul.pt
²  Observatoire de Genève, 51 ch. des Maillettes, 1290 Sauverny, Switzerland
³  Laboratoire d'Astrophysique de Marseille, Traverse du Siphon, 13013 Marseille, France
⁴  Laboratoire d'Astrophysique, Observatoire Midi-Pyrénées, 14 avenue Edouard Belin, 31400 Toulouse, France
⁵  Physikalisches Institut, Universität Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
⁶  Service d'Aéronomie du CNRS, BP 3, 91371 Verrières-le-Buisson, France
⁷  European Southern Observatory, Casilla 19001, Santiago 19, Chile
⁸  Laboratoire d'Astrophysique de l'Observatoire de Grenoble, 414 rue de la piscine, 38400 Saint Martin d'Hères, France

(Received 25 August 2004 / Accepted 10 September 2004)

Abstract
In this letter we present the discovery of a very light planetary companion to the star  Ara (HD 160691). The planet orbits its host once every 9.5 days, and induces a sinusoidal radial velocity signal with a semi-amplitude of 4.1 m s ^-1, the smallest Doppler amplitude detected so far. These values imply a mass of 14  (Earth-masses). This detection represents the discovery of a planet with a mass slightly smaller than that of Uranus, the smallest "ice giant" in our Solar System. Whether this planet can be considered an ice giant or a super-earth planet is discussed in the context of the core-accretion and migration models.

Key words: stars: individual: HD 160691 -- planetary systems -- techniques: radial velocities

SIMBAD Objects

© ESO 2004

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