Optimized and transformed power-2 limb-darkening law parameters, h₁ and h₂ as a functionof impact parameter, b. The values of T_eff, [Fe/H], logg and radius ratio, k, and the bandpass used for the simulation are noted in the title to each pair of panels. Note that the vertical scale on each axis is set by the median standard errors on h_1,obs and h_2,obs from Table A.1 (± 0.003 and ± 0.046, respectively). Also shown for the CHEOPS passband are the results for k = 0.9 (dashed line). The small spikes seen on the curves for the u′ passband are the result of numerical noise in the light curves at the few ppm level.