Quasi-elliptic trajectories in the gravitational field of a rotating star

A detailed derivation is given of formulas describing the trajectory of a test body moving closely to the ecliptic plane of a rotating star whose gravitational field is modeled by the Kerr metric. It is found that the quasi-elliptic orbit parameters and the revolution period noticeably change (as compared to the classical case), and an additional orbit precession emerges, though four orders of magnitude weaker than that of the Einstein-Schwarzschild case. © 2017, Pleiades Publishing, Ltd.