Analytical theories for near coplanar and polar circumbinary orbits
The recently discovered Kepler circumbinary systems and the circumbinary polar-ring debris disc in the 99 Herculis system call for the study of circumbinary orbits. As an approximation, it is advisable to investigate the problem with the assumption that the outer body is massless. In such a scheme, we briefly summarize the main characteristics of the evolution of the orbits and give the general so