Example spectra for a fictitious star (T_eff = 3000 K, log g = 5.0, R_* = 0.20 R_⊙, distance = 14 pc). Top: spectrum of the spotless photosphere. The blue circle and the red square mark the fluxes in the K2 and TESS wavelength band, respectively. Bottom: zoom onto the spectrum. The spectrum of the spotted photosphere is overplotted as a dashed gray line. The parameters of the spot are T_spot = 2500 K and f = 0.1. The fluxes in the K2 and TESS wavelength band, which includes the star spot, are shown as the light blue square and pink circle, respectively. The resulting, spot modulation amplitudes in the light curve are 5.96% for K2 and 6.73% for TESS.