BD+20 1790 b: Chronicle of an exoplanetarydiscovery

摘要

In this contribution we report evidence for a planetary companion around a young andactive late-type K star. Our group has been developing a study of stellar activity and kinematics forthis star over the past years. Previous results show a high level of stellar activity, with the presence ofprominence-like structures, spots on surface and strong flare events. Radial velocity (RV) variationswith a semi-amplitude of up to 1 km s~(-1)were detected. When the nature of these variations wereinvestigated it was found that they are not due to stellar activity. Based upon the analysis of bisectorvelocity span, as well as Ca ii H & K emission, we report that the best explanation for RV variationis the presence of a sub-stellar companion. The Keplerian fit of the RV data yields an orbital solutionfora close-in massive planet with an orbital period of 7.783 days. Also, the presence of this close-inmassive planet chould be an interpretation for the high level of stellar activity detected.