The ELODIE survey for northern extra-solar planets - II. A Jovian planet on a long-period orbit around GJ 777A

We present radial-velocity measurements obtained with the ELODIE and AFOE spectrographs for GJ777A (HD190360), a metal-rich ([Fe/H] = 0.25) nearby (d = 15.9 pc) star in a stellar binary system. A long-period low radial-velocity amplitude variation is detected revealing the presence of a Jovian planetary companion. Some of the orbital elements remain weakly constrained because of the smallness of the signal compared to our instrumental precision. The detailed orbital shape is therefore not well established. We present our best fitted orbital solution: an eccentric (e = 0.48) 10.7-year orbit. The minimum mass of the companion is 1.33 M-Jup.