Equatorial and halo orbits around an oblate magnetic planet

We calculate equatorial and halo orbits around an oblate magnetic planet. It is know that circular equatorial and halo orbits exist for a dust grain orbiting a spherical magnetic planet. However, the frequency of the orbit is constrained by the charge-mass ratio of the particle. If the oblateness of the planet is taken into account this constraint is modified or, in some cases, it disappears. The conditions of stability of the orbits are also modified.