Orbital Phase Dependence of Globular Cluster’s Tidal Radii

The orbits for a sample of 45 galactic globular clusters are calculated using positions and spatial velocities based on recent compilations as well as new measurements of their absolute proper motions. The perigalactic positions of each cluster are used to determine their theoretical tidal radii in the given galactic model. The orbital phase dependence between the theoretical and observed tidal radii is evidenced.