Where's the cusp? (Or CCD photometry of globular cluster cores).

UBVR CCD surface photometry for a sample of 11 globular clusters has been obtained at the Kitt Peak National Observatory #1 0.9 m telescope as part of a major study of globular cluster core structure. These data are being used to test for the presence of central cusps in the surface brightness profiles, which are expected to be present in clusters which have already undergone core collapse (Cohn and Hut 1984).