SOPHIE velocimetry of Kepler transit candidates. IX. KOI-415 b: a long-period, eccentric transiting brown dwarf to an evolved Sun

We report the discovery of a long-period brown-dwarf transiting companion of the solar-type star KOI-415. The transits were detected by the Kepler space telescope. We conducted Doppler measurements using the SOPHIE spectrograph at the Observatoire de Haute-Provence. The photometric and spectroscopic signals allow us to characterize a 62.14 ± 2.69 M_Jup brown-dwarf companion of an evolved 0.94 ± 0.06 M_⊙ star in a highly eccentric orbit of P = 166.78805 ± 0.00022 days and e = 0.698 ± 0.002. The radius of KOI-415 b is 0.79_-0.07^+0.12R_Jup , a value that is compatible with theoretical predictions for a 10 Gyr, low-metallicity and non-irradiated object.

Based on observations collected with the NASA Kepler satellite and with the SOPHIE spectrograph on the 1.93-m telescope at Observatoire de Haute-Provence (CNRS), France.Table 1 is available in electronic form at http://www.aanda.org