Ceres’ rotation solution under the gravitational torque of the Sun

Abstract

Available observations of the shape of Ceres show it as a rotationally symmetric oblate spheroid. However, deviations from axisymmetry even at the level of observational accuracy may show significant effects on its rotational dynamics. These presumed deviations can be accounted for in a purely analytical way by means of perturbation theory. In our approach, the spherical rotor is taken as the unperturbed part of the motion instead of the more common torque-free motion or uniaxial body approaches. This alternative allows us to compute an analytical solution for the rotation of Ceres under the gravitational pull of the Sun by proceeding with a successive elimination of the different angles, which only involves quadratures of straightforward computation.