YERKES OBSERVATORY

Yerkes Observatory is an astronomical observatory operated by the University of Chicago in Williams Bay, Wisconsin. The observatory, which calls itself "the birthplace of modern astrophysics,"was founded in 1897 by George Ellery Hale and financed by Charles T. Yerkes. It represented a shift in the thinking about observatories, from their being mere housing for telescopes and observers, to the modern concept of observation equipment integrated with laboratory space for physics and chemistry.

The Observatory has the largest refracting telescope successfully used for astronomy and has a collection of over 100,000 photographic plates. The present (2010) director of the observatory is Dr. Kyle M. Cudworth.

The principal instrument is a 40-in. refracting telescope, completed in 1897, the largest of its type in the world; its size is very near the practical limit for a refractor because of distortions caused by the weight of the lens itself. Other equipment includes a 41-in. and two 24-in. reflecting telescopes and a number of specialized instruments. Principal programs include astrometry, and studies of comets, galaxies, and the interstellar medium.