Nucleus brightness fitting in the inner coma of comet 41P. Left panel: innermost 40 × 40 pixel of the observed comet image on 2017 May 09.Middle panel: respective 40 × 40 pixel model image using the Moffat PSF, with the same flux levels as in the observed image. Right panel: ratio of the radial profiles between the simulated and observed image. Parameters of the simulated image are: nucleus brightness (Nucl = 17.5 mag), gradient of the inner coma flux (Grad = 0.83), FWHM of the PSF (6.12 pixels), and Moffat β parameter (MofB = 3.0). The plot shows the ratio of the normal pixel resolution of the model image (red line) to that of an oversampled (factor 5) version (black line).