where M is the mass of the SMBH and G the gravitational constant. The size R works out to be roughly one-half parsec (pc) (two light-years) for a kick of 1000 km/s and a SMBH mass of 100 million solar masses. The largest HCSSs would have sizes of about 20 pc, roughly the same as a large globular cluster, and the smallest would be about a thousandth of a parsec across, smaller than any known star cluster.