Diagnostics used for star-galaxy separation. A source is classified as a star if it fulfils at least four selection criteria. The panels illustrate (1) the distance with the matched Gaia-DR3 stars; (2) the colour–colour diagnostic; (3) the stellarity criterion provided by SourceExtractor; (4) the relation between the magnitude in the Kron-aperture and the maximum surface brightness; (5) the size of the objects; and (6) the SPREAD_MODEL sequence for point-like objects. The objects selected in each criterion are highlighted in red.