Example of GLS periodogram (top), ACF (middle), and CS (bottom) analyses performed to recover the rotational modulation of the light curve shown in Fig. 4, using the full time series. The GLS periodogram was normalised to account for the background contribution according to the method described in Sect. 2.2.1. The set of Gaussian profiles fitted on the GLS periodogram and the CS are shown in orange. The smoothed periodogram is shown in cyan, while the Gaussian profile fitted on it and centred on P_LS is shown in blue.