Lomb-Scargle periodogram constructed for the same star, KIC 9009514, as in Fig. 1. The vertical dotted line marks the value of P_rot = 1.211 days, provided in Nielsen et al. (2013). The periodogram running value S_L − S is calculated with ΔF_n, according to Eq. (23) in Carpintero (2021). The value of ⟨F(t)⟩, used in Eq. (1) is smoothed over a widened sliding time-window t − 3P_rot < t < t + 3P_rot, which also enables the detection of possible parasitic periodicities at timescales of < 6P_rot.