Time series of the Kepler star KIC 2852336 with solid black line denoting the 20-day moving average (upper panel) and the corresponding GLS power spectrum (lower panel). The frequency interval, which includes the periods between 1–90 days, is presented; the rotational periods of 9.5 d, 44 d and 58–61 d (indicated by black arrows), which may correspond to the Rieger cycle, are clearly seen.