Trajectories of particles leaving their circular orbits following an impulsive increase in luminosity from zero to that value (k = 1.45 for R = 5) at which the escape sphere and the Eddington capture sphere coincide. Particles initially in circular orbits at (or outside) the escape sphere leave the system on outward bound trajectories (thin dashed red line). Those from initial orbits inside the escape sphere, turn back and are captured by the ECS, on which they remain at rest in their final position (thick dots).