Distant source image motion due to gravitational field of the Galaxy   stars
  Gravitational field of stars of the Galaxy causes additional motions of images of extragalactic sources. For typical realization of stars this results in a small rotation of extragalactic reference frame in the direction of Galactic rotation. We estimate angular velocity of corresponding image motion and show that it is different in case of discrete and continuous matter distribution in the Galaxy. 
V.I.Zhdanov, E.V.Fedorova, A.N.Alexandrov