Profiles of outbursts Nos. 5−8 in GK Per. a), d), g), i) Light curve in the optical band (one-day means, intensity scale). The arrangement is identical to that in Fig. 2. Vertical bars in panel g) represent the CCD series plotted in Fig. 4. b), e) Moving averages of intensities in the ASM/RXTE data. The arrangement is identical to that in Fig. 2. c), f), h), j) One-day means of the BAT/Swift observations. The uncertainties given by the BAT team are given. Open points represent the measurements with u_BAT< 0.004 ct cm^-2 s^-1 in the gaps in panel h). See Sect. 3 for details. (This figure is available in color in the electronic edition.)