ASPCS
 
Back to Volume
Paper: Stellar distances and HIPPARCOS
Volume: 40, Inside the Stars, IAU Colloquium 137
Page: 324
Authors: Gomez, A. E.
Abstract: Consideration is given to Hipparcos, the astrometric satellite of the ESA, which is to provide absolute trigonometric parallaxes for about 100,000 stars brighter than the limiting V-magnitude 12.5. The principal types of stars observed by Hipparcos are summarized; different groups of spectroscopically peculiar stars and of variable stars are represented in the observing program. Among the observed stars, Hipparcos is measuring all stars brighter than V-magnitude 7, a survey of about 52,000 stars and nearby stars selected from specific catalogs such as the Gliese Catalog and the LHS and NLTT catalogs. The predicted standard errors on parallaxes are shown as a function of the H(P)-magnitude for a mission duration of 4 yr. The expected accuracies on the Hipparcos parallaxes will vary between 1 and 5 milliarcsec. For about 110 systems, individual masses will be derived with a relative accuracy better than 15 percent and, for 25 systems, better than 5 percent.
Back to Volume