{The young active star BD +20 1790 is believed to host a substellar
companion, revealed by radial-velocity measurements that detected the reflex
motion induced on the parent star. A complete characterisation of the
radial-velocity signal is necessary in order to assess its nature. We used
CORALIE spectrograph to obtain precise ($\sim$10 m/s) velocity measurements on
this active star, while characterizing the bisector span variations. Particular
attention was given to correctly sample both the proposed planetary orbital
period, of 7.8 days, and the stellar rotation period, of 2.4 days. A smaller
radial-velocity signal (with peak-to-peak variations $<$500 m/s) than had been
reported previously was detected, with different amplitude on two different
campaigns. A periodicity similar to the rotational period is found on the data,
as well as a clear correlation between radial-velocities and bisector span.
This evidence points towards a stellar origin of the radial-velocity variations
of the star instead of a baricentric movement of the star, and repudiates the
reported detection of a hot-Jupiter.