Gaia DR3 data within two degrees of the centre of Sculptor. (a) Distribution of sources on the sky. (b) Median number of astrometric observations (astrometric_matched_transits) matched to a given source. (c) Uncertainty on μ_δ as a function of G. The sequence at higher values corresponds to the area in panel (b) with fewer visits. The orange ellipse in panels (a) and (b) indicates the nominal tidal radius of Sculptor.