Upper panel: autocorrelation function of the CoRoT light curve. The period corresponding to the proposed f_rot rotational frequency is marked with a thick vertical line. The same scaling is used as for Fig. 9. Lower panels: sample consecutive cuts of the CoRoT light curve according to a period of 1/f_rot showing strong similarities. For better visibility the previous and following cuts are also plotted in grey, while the consecutive orders are shifted downwards by 5000 ppm.