Astrometry with the Space Telescope Wide-Field/Planetary Camera

Abstract

Although the Space Telescope Wide-Field/Planetary Camera is not primarily an astrometric instrument, it is expected to have some astrometric capability. Moreover, one of its possible astrometric applications is of unusually high scientific importance, namely, an attempt to detect the presence of planets around nearby stars. Let me therefore adopt that application as an example for discussing the anticipated astrometric performance of the camera system. It will be expeditious to make use of some diagrams that I have presented previously elsewhere, so part of the story may sound familiar (Baum 1979a, 1979b, 1980a, 1980b; Baum, Thomsen, and Kreidl 1981).