2023

The light propagation in plasma medium around stationary gravitating objects is studied in the geometrical optics limit. Static metrics with quadrupole moments are considered; however, most of our attention is on the stationary Hartle-Thorne metric and Kerr metric.

Their different effects on the light deflection are compared. The deflection angle is given in a general analytic form, and the detailed calculations are performed in the weak-field limits and illustrated graphically.

The trajectories of the light rays are constructed and compared, emphasizing the role of the quadrupole moment.