EDP Sciences
Free access
Volume 496, Number 2, March III 2009
Page(s) 527 - 531
Section Planets and planetary systems
DOI http://dx.doi.org/10.1051/0004-6361:200810669
Published online 14 January 2009
A&A 496, 527-531 (2009)
DOI: 10.1051/0004-6361:200810669

The HARPS search for southern extra-solar planets

XVII. Super-Earth and Neptune-mass planets in multiple planet systems HD 47 186 and HD 181 433
F. Bouchy1, M. Mayor2, C. Lovis2, S. Udry2, W. Benz3, J.-L. Bertaux4, X. Delfosse5, C. Mordasini3, F. Pepe2, D. Queloz2, and D. Segransan2

1  Institut d'Astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie, 98bis Bd Arago, 75014 Paris, France
    e-mail: bouchy@iap.fr
2  Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland
3  Physikalisches Institut Universitat Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
4  Service d'Aéronomie du CNRS, BP 3, 91371 Verrières-le-Buisson, France
5  Laboratoire d'Astrophysique, Observatoire de Grenoble, Université J. Fourier, BP 53, 38041 Grenoble, Cedex 9, France

Received 24 July 2008 / Accepted 20 November 2008

We report on the detection of two new multiple planet systems orbiting solar-like stars HD 47 186 and HD 181 433. The first system contains a hot Neptune of 22.78 $M_{\oplus}$ with a 4.08-day period and a Saturn of 0.35 $M_{\rm JUP}$ with a 3.7-year period. The second system contains a Super-Earth of 7.5 $M_{\oplus}$ with a 9.4-day period, a 0.64 $M_{\rm JUP}$ with a 2.6-year period, and a third companion of 0.54 $M_{\rm JUP}$ with a period of about 6 years. These detections increase to 20 the number of close-in low-mass exoplanets (below 0.1 $M_{\rm JUP}$) and strengthen the fact that 80% of these planets are in multiple planetary systems.

Key words: stars: planetary systems -- techniques: radial velocities -- stars: individual: HD 47 186 -- stars: individual: HD 181 433

© ESO 2009