Top panel: same as in Fig. 9, except that the stellar surface (μ = 0) is taken where the specific intensity has dropped by a factor of exp(1). The green dashed curves are the best fits to the wavelength-dependent profiles in grey. The solid red line is the best fit to the integrated limb-darkening profile (black line). Bottom panel: observed minus calculated values of the wavelength-dependent profiles (green curves) and the integrated profile (red curve).