  From multi-epoch WFPC2/HST observations we present astrometric measurements
of the absolute motion of the bulge stars. The presence of an extragalactic
point-source candidate allows us to measure the difference between the Oort
constants, A-B = Theta_0/R_0. We find: Theta_0/R_0 = 27.4 +/- 1.8 km/s/kpc.
