astrograph

An astrograph is a specialized photographic telescope designed for mapping the heavens. It is equipped with a photographic plateholder at the focal plane of its objective lens, allowing it to capture images of celestial objects. The primary use of an astrograph is to precisely record the positions of numerous faint stars, which are then compiled into catalogs. These catalogs serve as crucial reference points for more detailed astronomical photography. While astrographs are a type of telescope, they are specifically designed for astrometry, the branch of astronomy concerned with precise measurements of the positions and movements of celestial bodies.12