Astrometry with Hubble Space Telescope Fine Guidance Sensors—A Review**Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Abstract

Over the last 20 years, Hubble Space Telescope Fine Guidance Sensor interferometric astrometry has produced precise and accurate parallaxes of astrophysical interesting stars and mass estimates for stellar companions. We review parallax results, and binary star and exoplanet mass determinations, and compare a subset of these parallaxes with preliminary results. The approach to single-field relative astrometry described herein may continue to have value for targets fainter than the limit in the coming era of 20–30 m telescopes.