Distribution of ﹩\mathrm{log}{R}_{{\rm{HK}}}^{{\prime} }﹩ versus rotation period for different T_eff ranges. We mark the position of the Sun with a red ⋆ symbol for comparison. The red dotted line indicates the position of P_rot,sat and the red solid line is the fitted segmented function line. The error bars of ﹩\mathrm{log}{R}_{{\rm{HK}}}^{{\prime} }﹩ represent the standard deviations for stars with repeated measurements.