Doubly-symmetric periodic orbits in the spatial Hill's lunar problem with oblate secondary primary

Abstract: In this article we consider the existence of a family of doubly-symmetric periodic orbits in the spatial circular Hill's lunar problem, in which the secondary primary at the origin is oblate. The existence is shown by applying a fixed point theorem to the equations with periodical conditions expressed in Poincare-Delaunay elements for the double symmetries after eliminating the short periodic effects in the first-order perturbations of the approximated system.