The SOPHIE search for northern extrasolar planets. IX. Populating the brown dwarf desert

WILSON, P. A.; SAHLMANN, J.; BOISSE, I.; ARNOLD, L.; COURCOL, B.; DÍAZ, , R. F.; MOUTOU, C.; SÉGRANSAN, D.; SANTOS, N. C.; ASTUDILLO-DEFRU, N.; REY, J.; BOURRIER, V.; DELFOSSE, X.; FORVEILLE, T.; SANTERNE, A.; HÉBRARD, G.; MONTAGNIER, G.; BOUCHY, F.; BONFILS, X.; DELEUIL, M.; EHRENREICH, D.; PEPE, F.; UDRY, S.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2016 vol. 588

0004-6361

Radial velocity planet search surveys of nearby solar-type stars have shown a strong scarcity of brown dwarf companions within ~5 AU. There is presently no comprehensive explanation for this lack of brown dwarf companions; therefore, increasing the sample of such objects is crucial to understand their formation and evolution. Based on precise radial velocities obtained using the SOPHIE spectrograph at Observatoire de Haute-Provence we characterise the orbital parameters of 15 companions to solar-type stars and constrain their true mass using astrometric data from the Hipparcos space mission. The nine companions not shown to be stellar in nature have minimum masses ranging from ~13 to 70 MJup, and are well distributed across the planet/brown dwarf mass regime, making them an important contribution to the known population of massive companions around solar-type stars. We characterise six companions as stellar in nature with masses ranging from a minimum mass of 76 ± 4 MJup to a mass of 0.35 ± 0.03 M⊙. The orbital parameters of two previously known substellar candidates are improved.