Dependences of inflection point position on ratio between facular and spot disk-area coverage at the time of maximum area, S_fac∕S_spot, plotted for three values of the rotation period: 20 d (blue), 30 d (black), and 40 days (red). Shown are positions in days (upper panel) and ratios with respect to the rotation period (lower panel). Calculations are performed for a spot decay rate of 25 MSH day⁻¹, T_fac ∕T_spot = 3, and mean fractional disk-area spot coverage of 0.3%. As in Figs. 8–9 for each pair of S_fac ∕S_spot and rotation periods values, five realization of active regions emergences are shown. Red, black, and blue lines indicate positions of the inflection points averaged over corresponding five realizations. A small deviation of 20 d curve from 30 d and 40 d curves in the lower panel at high S_fac ∕S_spot values can be explained by the insufficient cadence of light curves (4 points per day) for 20 d rotation period and aliasing effect.