Tidal limit of stellar systems in two-power density models

As the generalization of gravitational effects on the point mass systems, we want to study the tidal effect exerted on an extended stellar system using spherical and axisymmetric elliptical models. Considering the Isochrone and Plummer models for a passing extended stellar system, the tidal distance and the equipotential surface are found. The corresponding critical surfaces and maps are plotted for different cases. There are different results; some of them may be used in describing stellar system deformation.