Out-of-plane equilibria in the restricted five-body problem with radiation pressure

The photogravitational restricted five-body problem is employed to describe the motion of an infinitesimal test particle in the special case where two of the primaries are radiation sources. The four primaries mi, i = 0, , 3 three of which have equal masses (m1 = m2 = m3 = m) are located at the vertices of an equilateral triangle, while the fourth one with a different mass m0 is located at the centre of this configuration (Ollongren's configuration). The fifth body of negligible mass moves in the resultant force field of the primaries and does not affect the motion of the four bodies (primaries). We consider that the central primary body m0 and one of the peripheral bodies m1 are radiation sources. The equilibrium points lying out of the orbital plane of the primaries as well as the allowed regions of motion as determined by the zero velocity curves are studied numerically. Finally, the stability of these points is also examined.