Effect of radiation on the nonlinear stability zones of the Lagrangian equilibrium points

The nonlinear stability zones of the triangular Lagrangian points are deter mined numerically and the effect of radiation of primaries is considered, i n addition to the known effect of mass distribution, using the photogravita tional restricted three-body problem model. It is found that radiation also has a considerable effect reducing the stability zones. In cases of resona nces, these zones are reduced to negligible size for some parameter values within the linear stability regions.