Since the black hole at the center of the HCSS is essentially invisible, an HCSS would look very similar to a faint cluster of stars. Determining that an observed star cluster is a HCSS requires measuring the orbital velocities of the stars in the cluster via their Doppler shifts and verifying that they are moving much faster than expected for stars in an ordinary star cluster. This is a challenging observation to make because an HCSS would be relatively faint, requiring many hours of exposure time even on a 10m class telescope.