Yerkes Observatory

Yerkes Observatory

Aerial view of Yerkes Observatory main building.
Organization	University of Chicago
Code	754
Location	Williams Bay, Wisconsin, USA
Coordinates
Altitude	1050 feet (334 m)
Weather	See the Clear Sky Chart
Website	astro.uchicago.edu/yerkes/
Telescopes
40-inch (102 cm) refractor 40-inch (102 cm) reflector 24-inch (61 cm) reflector 10-inch (25 cm) Cassegrain reflector 7-inch (18 cm) Schmidt camera

1897 photo of the 100 cm (40 in) refractor at the Yerkes Observatory.

2006 photo of the 100 cm (40 in) refractor at the Yerkes Observatory

Yerkes Observatory is an astronomical observatory in Williams Bay, Wisconsin operated by the University of Chicago Department of Astronomy and Astrophysics. The observatory, which calls itself "the birthplace of modern astrophysics," was founded in 1897 by astronomer George Ellery Hale and financed by businessman 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 world's largest refracting telescope successfully used for astronomy and a collection of over 170,000 photographic plates. The director of the observatory is Doyle "Al" Harper. Notable astronomers who have conducted research at Yerkes include Edwin Hubble (who did his graduate work at Yerkes and for whom the Hubble Space Telescope was named), Subrahmanyan Chandrasekhar (for whom the Chandra Space Telescope was named), prolific Russian-American astronomer Otto Struve, and the well-known twentieth-century popularizer of astronomy Carl Sagan.

Telescopes

Comparison of nominal sizes of primary mirrors of the Yerkes Observatory and some notable optical telescopes (click for detail)

Yerkes Observatory's 100 cm (40 in) refracting telescope was built by the renowned refracting telescope company Alvan Clark & Sons. It 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 mounting and tube for the 100-centimeter (40 in) telescope was exhibited at the 1893 World's Columbian Exposition in Chicago before being installed in the observatory. The grinding of the lens was completed later.

The observatory also houses 100 cm (40 in) and 61 cm (24 in) reflecting telescopes. Several smaller telescopes are used for educational purposes.

Research

Research conducted at Yerkes includes work on the interstellar medium, globular cluster formation, infrared astronomy, and near-Earth objects. The University of Chicago also maintains an engineering center in the observatory, dedicated to making and maintaining scientific instruments. In 2012 the engineers completed work on the High-resolution Airborne Wideband Camera (HAWC), which will be an integral part of the Stratospheric Observatory for Infrared Astronomy (SOFIA). Researchers also use the Yerkes collection of over 170,000 archival photographic plates that date back to the 1890s.

Development and preservation plans

In March 2005, the University of Chicago announced plans to sell the observatory and its land on the shore of Geneva Lake. Two purchasers had expressed an interest: Mirbeau, an East Coast developer that wanted to build luxury homes, and Aurora University, which has a campus straddling the Williams Bay property. The Geneva Lake Conservancy, a regional conservation and land trust organization, maintained that it was critical to save the historic Yerkes Observatory structures and telescopes for education and research, as well as to conserve the rare undeveloped, wooded lakefront and deep forest sections of the 310,000-square-meter (77-acre) site. On June 7, 2006, the University announced it would sell the facility to Mirbeau for US$8 million with stipulations to preserve the observatory, the surrounding 120,000 m² (30 acres), and the entire shoreline of the site. Under the Mirbeau plan, a 100-room resort with a large spa operation and attendant parking and support facilities was to be located on the 36,000-square-meter (9-acre) virgin wooded Yerkes land on the lakeshore—the last such undeveloped, natural site on Geneva Lake's 34-kilometer (21-mile) shoreline. About 70 homes were to be developed on the upper Yerkes property surrounding the historic observatory. These grounds had been designed more than 100 years previously by John Olmsted, the brother of famed landscape architect Frederick Law Olmsted, designer of New York's Central Park. Ultimately, Williams Bay's refusal to change the zoning from education to residential caused Mirbeau to abandon its development plans.

In view of the public controversy surrounding the development proposals, the university suspended these plans in January 2007. The university's department of astronomy and astrophysics then formed a study group, including representatives from the faculty and observatory and a wide range of other involved parties, to plan for the operation of a regional center for science education at the observatory. The study group began its work in February 2007 and issued its final report November 30, 2007. The report recommended creating a formal business plan to ensure the financial viability of the proposed science education center, establishing ownership of the proposed center before initiating plans for creating it, and forming a partnership between the University of Chicago and local interests to plan for the center. It also suggested that some lakefront and woods parcels could be sold for residential development.

See also

• List of largest optical refracting telescopes
• List of observatories

External links

Media related to at Wikimedia Commons

• Yerkes Observatory (official site).
• Description and history from the National Park Service.
• Save Yerkes
• Yerkes Study Group
• Geneva Lake Conservancy