Illustration of a stellar on-axis activity model for a solar-like star simulated for two years. (a) Spot emergence diagram with the black dots being their latitudinal location and relative sizes at emergence with respect to the stellar surface. (b) Stellar surface area covered by spots (in percentage). (c) Relative flux darkening by the spot coverage (in ppt) as function time. (d) Relative flux brightening by stellar flares (in ppt) as function of time.