Periodograms of the radial velocity. The upper panel shows the raw periodogram, the middle panel the periodogram of the residuals after subtracting the 8.7 d signal, and the lower panel the periodogram of the residuals after subtracting the 43 d signal present in the middle panel. Red regions show the periods of the measured rotation and magnetic cycle. Red dotted line for a 10% false alarm probability; green dashed line for 1%, and blue thick line for 0.1%.