Stellar density profile of the GC H4 from HST photometry. The gray line is a King-profile fit to the data at radii beyond r_GC = 12″. The red line indicates the background level that we determine from the stellar density outside the tidal radius of the cluster. The white area in the figure shows the radial zone from which we pick our targets. At smaller radii, the cluster is not resolved with ground-based telescopes, and the probability that a star at larger radii is a member of the system is very low.