The HARPS search for southern extra-solar planets - XV. Six long-period giant planets around BD-17 0063, HD20868, HD73267, HD131664, HD145377, and HD153950

C. Moutou, M. Mayor, G. Lo Curto, S. Udry, F. Bouchy, W. Benz, C. Lovis, D. Naef, F. Pepe, N. C. Santos

Resumo
We report the discovery of six new substellar companions of main-sequence stars, detected by multiple Doppler measurements with the instrument HARPS installed on the ESO 3.6 m telescope, La Silla, Chile. These extrasolar planets orbit the stars BD-17 0063, HD20868, HD73267, HD131664, HD145377, and HD153950. The orbital characteristics that reproduce the observed data are presented, as well as the stellar and planetary parameters. Masses of the companions range from 2 to 18 Jupiter masses, and periods range from 100 to 2000 days. The observational data are carefully analysed for activity-induced effects, and we conclude that the observed radial velocity variations are of exoplanetary origin. Of particular interest is the very massive planet (or brown-dwarf companion) orbiting the metal-rich HD131664 with m₂ sin i = 18.15 M_Jup and a 5.34-year orbital period. These new discoveries are consistent with the observed statistical properties of exoplanet samples known so far.

Palavras chave
stars: planetary systems, techniques: radial velocities, techniques: spectroscopic, stars:, general

Astronomy and Astrophysics
Volume 496, Página 513
março 2009

>> ADS>> DOI