* Astronomy

Title: SOPHIE velocimetry of Kepler transit candidates IV. KOI-196b: a non-inflated hot-Jupiter with a high albedo
Authors: A. Santerne, A. S. Bonomo, G. Hébrard, M. Deleuil, C. Moutou, J.-M. Almenara, F. Bouchy, R. F. Díaz

We report the discovery of a new hot-Jupiter, KOI-196b, transiting a solar-type star with an orbital period of 1.855558 days ±0.6s thanks to public photometric data from the Kepler space mission and new radial velocity observations obtained by the SOPHIE spectrograph mounted on the 1.93-m telescope at the Observatoire de Haute-Provence, France. The planet KOI-196b, with a radius of 0.841±0.032 Jupiter radii and a mass of 0.49±0.09 Jupiter masses, orbits a G2V star with R* = 0.996±0.032 solar radii, M*= 0.94±0.09 Solar masses, [Fe/H] = -0.10±0.16 dex, Teff= 5660±100 K and an age of 7.7±3.4 Gy. KOI-196b is one the rare close-in hot-Jupiters with a radius smaller than Jupiter suggesting a non-inflated planet. The high precision of the Kepler photometry permits us to detect the secondary transit with a depth of 64 +10/-12 ppm as well as the optical phase variation. We find a geometric albedo of Ag = 0.30±0.08 which is higher than most of the transiting hot-Jupiters with a measured Ag. Assuming no heat recirculation, we find a day-side temperature of Tday = 1930±80 K. KOI-196b seems to be one of the rare hot-Jupiters located in the short-period hot-Jupiter desert.

Read more (1464kb, PDF)