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.
Yerkes Observatory is most famous for its 102 cm (40 inch) refracting telescope built by the master optician Alvan Clark. This is the largest refracting telescope used for scientific research (a larger demonstration refractor, the Great Paris Exhibition Telescope of 1900, was exhibited at the Paris Universal Exhibition of 1900). The 40-inch telescope was exhibited at the 1893 World's Columbian Exposition in Chicago before being installed in the observatory.In addition to the Yerkes refractor, the observatory also houses 102 cm (40 inch, referred to as the "41 inch" to prevent confusion) and 61 cm (24 inch) reflecting telescopes. Several smaller telescopes are used for educational outreach purposes.
Present research activity includes work on the interstellar medium, globular cluster formation, infrared astronomy, and near-Earth objects. Additionally, the University of Chicago maintains an engineering center in the observatory, dedicated to making and maintaining scientific instruments. As of 2011, the engineers are working on the High-resolution Airborne Wideband Camera (HAWC), which will be an integral part of Stratospheric Observatory for Infrared Astronomy (SOFIA). Research is also done utilizing Yerkes' collection of over 150,000 archival photographic plates that date back to the 1890s.
Yerkes Observatory is the setting for about seven minutes of the 1996 movie Chain Reaction.One of the principal characters, Maggie McDermott, is first seen looking through the big refractor.The movie features a gunfight on the roof of Yerkes Observatory and an airboat chase across frozen Geneva Lake.