Comparison between the maximum magnetic flux (Φ) and emergence rate (dΦ_e/dt) of sunspots and star spots on solar-type stars. Black points, triangles, and crosses are the sunspot observational data taken from Otsuji et al. (2011), Toriumi et al. (2014), and Norton et al. (2017), respectively. Blue and red circles correspond to the spots analyzed in this study with P_rot < 7 days and P_rot > 7 days, respectively. Solid (dΦ_e/dt ∝ Φ^0.3) and dashed (dΦ_e/dt ∝ Φ^0.5) lines are scaling relations derived by Norton et al. (2017) and Otsuji et al. (2011), respectively. The standard deviations of the star-spot data compared with the scaling laws are 7.1 × 10²⁰ and 9.5 × 10²⁰ for Norton’s and Otsuji’s scaling laws, respectively. Dotted lines are the upper and lower 95% confidence intervals for the sunspot observations, and 76% of the star spots are located in the extrapolation of this 95% confidence interval.