Astrometry

Combining their own observations with others made by leading astronomers around the world at more than 200 observatories since1795, the Staff of the Dudley Observatory produced two major reference works widely used by astronomers around the world, the Preliminary General Catalog of 6788 Stars (1909), and the General Catalog of 33,343 Stars (1937).

This work was supported by the Carnegie Institution of Washington, and from 1905 until 1937 the Observatory served as the Department of Meridian Astrometry of the Carnegie Institution. In that capacity, it operated the San Luis Observatory from 1909 to 1913, where meridian circle observations were made with the Dudley Observatory's Olcott Meridian Circle.

The results of these observations, published as the San Luis Catalog of 15,333 Stars for the Epoch 1910 (1928). When these are combined with the subsequent Albany Catalog of 20,811 Stars for the Epoch 1910 (1931) they form the sole example in the history of astronomy of the precise position and proper motion determination of all stars visible to the unaided eye with a single high precision telescope.;