Suitability of the King Law for the globular clusters NGC 6171, NGC 5466, and M92

We have studied the suitability of a King law for the distributions of the apparent stellar density in the three globular clusters NGC 6171, NGC 5466, and M92 based on star counts to various limiting stellar magnitudes B. The density distributions cannot be adequately described by the King law. The parameters r(t) (the tidal radius of the cluster) and r(c) (the core radius) depend on the limiting B magnitude for counts of faint cluster stars below the transition region between the subgiant branch and the main-sequence turnoff in the (V, B-V) diagram. Variation of these parameters is similar to variation of the sizes of the cluster spatial zones introduced by Kholopov.