Fit to the light curve and supernova of GRB 180728A. Magnitudes are in the AB system and corrected for Galactic foreground extinction, and time is in the observer frame. For reasons of clarity, light curves in each filter are offset by the magnitude values noted in the legend. Starting at ≈300 s, the light curve in all bands except for H and K is fitted with a broken power law plus individual SN component. The dashed line for the white filter is an extrapolation because the points at > 4 days were not fitted. See text for details.