The HARPS search for southern extra-solar planets
XXXVII. Five new long-period giant planets and a system update

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

Abstract
We describe radial-velocity time series obtained by HARPS on the 3.60 m telescope in La Silla (ESO, Chile) over ten years and report the discovery of five new giant exoplanets in distant orbits; these new planets orbit the stars HD 564, HD 30669, HD 108341, and BD -114672. Their periods range from 492 to 1684 days, semi-major axes range from 1.2 to 2.69 AU, and eccentricities range from 0 to 0.85. Their minimum mass ranges from 0.33 to 3.5 M_Jup. We also refine the parameters of two planets announced previously around HD 113538, based on a longer series of measurements. The planets have a period of 663 ± 8 and 1818 ± 25 days, orbital eccentricities of 0.14 ± 0.08 and 0.20 ± 0.04, and minimum masses of 0.36 ± 0.04 and 0.93 ± 0.06 M_Jup. Finally, we report the discovery of a new hot-Jupiter planet around an active star, HD 103720; the planet has a period of 4.5557 ± 0.0001 days and a minimum mass of 0.62 ± 0.025 M_Jup. We discuss the fundamental parameters of these systems and limitations due to stellar activity in quiet stars with typical 2 m s^-1 radial velocity precision.

Keywords
planetary systems – techniques: radial velocities – techniques: spectroscopic – methods: observational

Astronomy and Astrophysics
Volume 576, Page A48_1
April 2015

DOI: 10.1051/0004-6361/201424965
ADS Bibliographic code: 2015A%26A...576A..48M