GAIA and Population II Visual Binaries
  The results of a kinematical population classification of 497 Hipparcos orbital binaries are discussed. Less than 10% of the stars from the sample belong to the thick disk. Only seven stars have halo kinematics. There are no direct dynamical mass determinations for extreme halo stars. Some suggestions, concerning Population II visual binaries for which ground-based astrometric observations in combination with GAIA data will be useful in the future for the better determination of orbits for long period Population II binaries, are offered. 
Antanas Bartkevicius, Arturas Gudas