21. He made major contributions to astrometry . 22. This is done using astrometry , which is the practice of measuring the position of stars. 23. The science of actually measuring positions of celestial objects in the sky is known as astrometry . 24. Research has focused on stellar characteristics, astrometry , and refining the limits of possible planets. 25. Initially the observatory was dedicated to astrometry , geodetic and meteorological observation and tracking the time. 26. It will also from 2011 be part of the International VLBI Service for Geodesy and Astrometry . 27. Those shifts are very large in comparison to the measurement precisions that are required for astrometry . 28. In some specialized cases, such as astrometry , FGSs can also be used as scientific instruments. 29. Primary work consists of planetary, deep sky, NEO studies, astrometry , photometry and astrophotography. 30. Based on parallax measurements from the Hipparcos astrometry satellite, this star is located about from the Earth.
