in Fig. 9 by arrows. Although the two short such intervals are well defined in the ASM light curve (MJD 50280-50311 and MJD 50730-50750 respectively), the boundaries of the long one are not so clear. We define its start as the time after which [*all*]{} PCA observation intervals show no structure in the 1s light curves, and its end as the time after which structure in the time variability is observed again in the PCA. This leads to the following start-end times: MJD 50410-50550, corresponding to observations K-04-00 to K-21-01. Observation K-03-00, the last before this period, shows a clear quasi-periodic structure corresponding to class $\rho$, and observation K-22-00, the first after this interval, shows again a quasi-periodic structure, but classified as class $\alpha$. Consistently, we applied the same method to re-define the time boundaries of the two shorter intervals, in order not to limit ourselves to the flat-bottom part of the light curves. We obtained the following time intervals: MJD 50275-50313 and MJD 50729-50750 respectively. We subdivided the observations of class $\chi$ into four sub-classes: $\chi_1$, $\chi_2$, $\chi_3$ correspond to the three quiet intervals (in time sequence), while $\chi_4$ comprises the remaining observation intervals, a number of which are 