HST Proper Motion of Andromeda III: Another Satellite Co-orbiting The M31 Satellite Plane

Dana I. Casetti-Dinescu, Marcel S. Pawlowski, Terrence M. Girard +5

We measure the absolute proper motion of Andromeda III using ACS/WFC and WFPC2 exposures spanning an unprecedented 22-year time baseline. The WFPC2 exposures have been processed us…