Window function (top panel) and Lomb-Scargle periodograms of the successively pre-whitened Hermes BIS measurements. The three periods shown in Fig. 9 are indicated by vertical dashed red lines. The period subtracted in the previous step is marked by a solid black line in the following periodogram. Other notable peaks in the 2nd and 3rd panel from the top include the peak at twice P_puls (2nd panel) and at twice P_40d (third panel).