Influence of mass multipole moments on the deflection of a light ray by an isolated axisymmetric body

Future space astrometry missions are planned to measure positions and/orparallaxes of celestial objects with an accuracy of the order of themicroarcsecond. At such a level of accuracy, it will be indispensable to takeinto account the influence of the mass multipole structure of the giant planetson the bending of light rays. Within the parametrized post-Newtonian formalism,we present an algorithmic procedure enabling to determine explicitly thisinfluence on a light ray connecting two points located at a finite distance.Then we specialize our formulae in the cases where 1) the light source islocated at space infinity, 2) both the light source and the observer arelocated at space infinity. We examine in detail the cases where the unperturbedray is in the equatorial plane or in a meridian plane.Comment: 9 pages. Submitted to Physical Review