The CORALIE survey for southern extra-solar planets VI. New long period giant planets around HD 28185 and HD 213240

In this paper we present giant planetary companions to the stars HD 28185 and HD 213240. Both candidates were discovered in the context of the CORALIE extra-solar planet search programme. The planet around HD 28185, with a minimum mass of 5.7 M_Jup is one of the first long period planets (P=383 days) discovered so far orbiting its host star in a nearly circular trajectory. On the other hand, the planet around HD 213240, with a 951-day period orbit, an eccentricity of 0.45, and a minimum mass of 4.5 M_Jup, is more typical of the up to now discovered long period systems. Based on observations collected at the La Silla Observatory, ESO (Chile), with the CORALIE spectrograph at the 1.2-m Euler Swiss telescope.