Rotational modulation of 55 Cnc in season 9 optical photometry (upper panel, P_* = 40.3 days) and in the Hα index (lower panel, P_* = 38.8 days). Data has been corrected for the stellar magnetic cycle and for the transit of 55 Cnc e (upper panel), then phase-folded to the periods detected in each dataset individually. Binned data points (black points) allow for a better comparison with the best-fit sine variations (red line).