The SOPHIE search for northern extrasolar planets. IX. Populating the brown dwarf desert
Bouchy, F.; Deleuil, M.; Moutou, C.; Montagnier, G.; Sahlmann, J.; Ségransan, D.; Bonfils, X.; Ehrenreich, D.; Santos, N. C.; Udry, S.; Pepe, F.; Bourrier, V.; Hébrard, G.; Boisse, I.; Delfosse, X.; Díaz, R. F.; Forveille, T.; Arnold, L.; Astudillo-Defru, N.; Rey, J.; Santerne, A.; Wilson, P. A.; Courcol, B.
France, Portugal, Spain, Switzerland, United States
Abstract
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.
Based on observations collected with the SOPHIE spectrograph on the 1.93 m telescope at Observatoire de Haute-Provence (CNRS), France, by the SOPHIE Consortium.The radial velocity measurements are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/588/A144