  A model approach to the description of static stars filled with a charged
Pascal perfect fluid within the framework of general relativity is
investigated. The metric is written in Bondi's radiation coordinates. The
gravitational equations are reduced to a nonlinear oscillator equation after
transfomation to a new variable as a function of the radial coordinate. It is
shown that in this case exact solutions of the Einstein-Maxwell equations for a
concrete energy density distribution law of the charged fluid may be obtained
as solution of the harmonic oscillator equation.
