Close-up of the spatial distribution of Crater 2. The left-hand panel shows the density map of all stars that fall within the isochrone mask, i.e. RGB + RHB. The middle panel shows RHB stars only – these are the most numerous stars above the limiting magnitude of the ATLAS survey. The rightmost panel gives the distribution of the BHB candidate stars as selected using the blue box shown in the right-hand panel of Fig. 3. The red solid (dashed) line indicates the half-light radius (twice the half-light radius), and the colour scale in the bottom shows the number of stars per bin.