Astrometry is on the threshold of great changes due to the fact that this decade, alone, is witnessing an improvement of stellar positions equivalent to the total improvement of the previous two centuries. The Hipparcos Satellite has concluded its observations, and the catalog is in preparation. Preliminary results assure that the Hipparcos catalog will provide positions, parallaxes and annual proper motions for over 100,000 stars with accuracies of 1.5 milliarcseconds. In addition, the Tycho catalog will provide positions of about 30 milliarcseconds accuracy for over 1 million stars, and...
Astrometry is on the threshold of great changes due to the fact that this decade, alone, is witnessing an improvement of stellar positions equivalent ...
International Astronomical Union Erik Hxg P. Kenneth Seidelmann
This text records the recent events in the development of astrometry. The results of space missions in astrometry, Hipparcos and some results from the Hubble Space telescope are presented. Combined with ground-based results, this provides astrometry results at milliarcsecond resolution. At the same time, the extragalactic reference frame, based on very long baseline interferometry radio positions, is being introduced as the fundamental reference frame. It is now also evident that future optical interferometry space missions can provide an additional improvement in future of orders of...
This text records the recent events in the development of astrometry. The results of space missions in astrometry, Hipparcos and some results from the...