Surface density profiles along the major and minor axis of the NGC 253 disk, as labelled. The profiles are constructed from catalog A, considering only probable members of NGC 253 (stars below the solid line in Fig. 6), and the error bars show the ± 1σ Poissonian uncertainty. The star counts along the major axis are performed within a horizontal stripe defined by 8250 ≤ Y ≤ 9250 pixels, corresponding to a width of ≃5.7 kpc. The central region is excluded due to crowding. The minor axis profiles are extracted from a stripe at 3800 ≤ X ≤ 6800 pixels. At a distance of ≃35 kpc from the center the number density is nearly the same in the two orthogonal directions. The dotted black line shows the density of foreground/background objects measured on subregions 1+4 in Fig. 11 in the same selected part of the CMD.