The CORALIE survey for southern extra-solar planets - VI. New long period giant planets around HD28185 and HD213240

In this paper we present giant planetary companions to the stars HD28185 and HD213240. Both candidates were discovered in the context of the CORALIE extra-solar planet search programme. The planet around HD28185, 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 HD213240, 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.