We performed an intensive radial velocity monitoring of XO-2S, the wide companion of the transiting planet-host XO-2N, using HARPS-N at TNG in the framework of the GAPS programme. The radial velocity measurements indicate the presence of a new planetary system formed by a planet that is slightly more massive than Jupiter at 0.48 au and a Saturn-mass planet at 0.13 au. Both planetary orbits are moderately eccentric and were found to be dynamically stable. There are also indications of a long-term trend in the radial velocities. This is the first confirmed case of a wide binary whose components both host planets, one of which is transiting, which makes the XO-2 system a unique laboratory for understanding the diversity of planetary systems.
|Titolo:||The GAPS programme with HARPS-N at TNG : 4., a planetary system around XO-2S|
|Parole Chiave:||Planetary systems; Stars: individual: XO-2N; Stars: individual: XO-2S; Techniques: radial velocities|
|Settore Scientifico Disciplinare:||Settore FIS/05 - Astronomia e Astrofisica|
|Data di pubblicazione:||2014|
|Digital Object Identifier (DOI):||10.1051/0004-6361/201424339|
|Appare nelle tipologie:||01 - Articolo su periodico|