Folding search of periodicities in the 2–10 keV MAXI light curve between 22.78 and 26.92 d. We adopted 16 phase-bins per period for the trial folded light curves and a resolution of the period search of 0.001 d. The vertical solid blue and dashed blue lines correspond to the period 24.27 ± 0.03 d suggested by Corbet et al. (2010). Three peaks of χ² are detected: at 24.53 d (vertical red line), at 25.6 d (vertical dashed green line), and at 24 d (vertical solid green line). The latter period is an instrumental artifact (see text). The bin time is 1.53 d.