Dr. Norbert Zacharias
IAU vice-president commission 8 (Astrometry)
Astrometry is the branch of astronomy which deals with positions and motions of celestial bodies. Areas of research in astrometry can be categorized into ground-or space-based, by wavelength (radio, optical, IR astrometry), or technique, including direct imaging and interferometry. Targets of research in astrometry range from satellites orbiting Earth to solar system astrometry to galactic and extragalactic kinematics and dynamics. Astrometry forms the basis of astrophysics by providing trigonometric parallaxes (distances) and masses of celestial bodies.