The CORALIE survey for southern extra-solar planets

We report the detection of two very eccentric planets orbiting HD 4113 and HD 156846 with the CORALIE Echelle spectrograph mounted on the 1.2-m Euler Swiss telescope at La Silla. The first planet, HD 4113 b, has minimum mass of m sin i = 1.6 ± 0.2 MJup, a period of P = 526.59 ± 0.21 days and an eccentricity of e = 0.903 ± 0.02. It orbits a metal rich G5V star at a = 1.28 AU, which displays an additional radial velocity drift of 28 m s-1 yr-1 observed during 8 years. The combination of the radial-velocity data and the non-detection of any main sequence stellar companion in our high contrast images, taken at the VLT with NACO/SDI, characterizes the companion as a probable brown dwarf or as a faint white dwarf. The second planet, HD 156846 b, has minimum mass of m sin i = 10.45 ± 0.05 MJup, a period of P = 359.51 ± 0.09 days, an eccentricity of e = 0.847 ± 0.002 and is located at a = 1.0 AU from its parent star. HD 156846 is a metal rich G0 dwarf and is also the primary of a wide binary system (a > 250 AU, P > 4000 years). Its stellar companion, IDS 17147-1914 B, is a M4 dwarf. The very high eccentricities of both planets can be explained by Kozai oscillations induced by the presence of a third object.