The detection extra-solar planets through radial-velocity searches is likely limited by the intrinsic magnetic activity of the host stars. The correlated « noise » that arises from their natural radial-velocity variability (jitter) can easily mimic and hide the orbital signals of super-Earth and Earth-mass exoplanets, or even of a giant planets for the most active and young stars.

The modeling of the RV jitter is thus essential to extrasolar planets searches. I will present here different techniques used to filter out the RV activity jitter and that allowed to unveil one of the youngest hot Jupiter discovered so far, V830 Tau b.