Висконсин штатындағы Йеркес астрономиялық обсерваториясы

Astronomical observatory in Wisconsin, USA

Yerkes Observatory ('/j//ɜːr//k//iː//z/ YURkeez) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 to 2018. Ownership was transferred to the non profit Yerkes Future Foundation (YFF) in May 2020, which began restoration and renovation of the historic building and grounds. Re opening for public tours and programming began May 27, 2022. The observatory, often called "the birthplace of modern astrophysics," was founded in 1892 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 early 20th century concept of observation equipment integrated with laboratory space for physics and chemistry analysis. The observatory's main dome houses a doublet lens refracting telescope, the second largest refractor ever successfully used for astronomy. The largest lens is the Swedish 1 m Solar Telescope. There are several smaller telescopes – some permanently mounted – that are primarily used for educational purposes. The observatory also holds a collection of over 170,000 photographic plates. The Yerkes 40 inch was the largest refracting type telescope in the world when it was dedicated in 1897, although there had been several larger reflecting telescopes. During this time, there were many questions about the merits of the various materials used to construct and design telescopes. Another large telescope of this period was the Great Melbourne Telescope, which was a reflector. In the United States, the Lick refractor had just a few years earlier come online in 1888 in California with a 91 cm lens. Prior to its installation, the telescope on its enormous German equatorial mount was shown at the World's Columbian Exhibition in Chicago during the time the observatory was under construction. The observatory was a center for serious astronomical research for more than 100 years. By the 21st century, however, it had reached the end of its research life. The University of Chicago closed the observatory to the public in October 2018. In November 2019, "an agreement in principle" was announced that the university would transfer Yerkes Observatory to the non profit Yerkes Future Foundation (YFF). The transfer of ownership took place on May 1, 2020.

In the 1860s Chicago became home of the largest telescope in America, the Dearborn refractor. It was later surpassed by the U. S. Naval Observatory's 26 inch, which would go on to discover the moons of Mars in 1877. There was an extraordinary increase of larger telescopes in finely furnished observatories in the late 1800s. In the 1890s various forces came together to establish an observatory of art, science, and superlative instruments in Williams Bay, Wisconsin. The telescope was surpassed by the Harvard College Observatory, reflector less than ten years later, although it remained a center for research for decades afterwards. In addition to the large refractor, Yerkes also conducted a great amount of Solar observations.

Yerkes Observatory's 40 inch (102 cm) refracting telescope has a doublet lens produced by the optical firm Alvan Clark & Sons and a mounting by the Warner & Swasey Company. It was the largest refracting telescope used for astronomical research. In the years following its establishment, the bar was set and tried to be exceeded; an even larger demonstration refractor, the Great Paris Exhibition Telescope of 1900, was exhibited at the Paris Universal Exhibition of 1900. However, this was not much of a success, was dismantled, and did not become part of an active University observatory. The mounting and tube for the 40 inch 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.

A 12 inch refractor was moved to Yerkes from Kenwood Observatory in the 1890s. The clear aperture of the telescope was actually 23.5 inches. At one point the Observatory had an IBM 1620 computer, which it used for three years. Later, there was another 24 inch reflecting telescope by Boller & Chivens. This was contracted in the early 1960s under direction of observatory director W. Albert Hiltner. This telescope was installed in one of the smaller Yerkes domes, and it is known to have been used for visitor programs. This was a design by Boller & Chivens with Cassegrain optical setup, with a 24 inch (61 cm) clear aperture and is on an off axis equatorial mount. A 7 inch (18 cm) diameter aperture Schmidt camera was also at Yerkes Observatory. The Snow Solar Telescope was first established at Yerkes Observatory, and then later moved in 1904 to California. The telescope had two objective lens for photography, one doublet of 10 inches aperture and another of 6.5 inches; in addition there is a 5 inch guide scope for visual viewing. The Bruce astrograph lenses were made by Brashear with Mantois of Paris glass blanks, and the lenses were completed by the year 1900.

The Observatory was dedicated on October 21, 1897, and there was a large party with university, astronomers, and scientists. Before the dedication a conference of astronomers and astrophysicists was hosted at Yerkes Observatory, and took place on October 18–20, 1897. This is noted as a precursor to the founding of the American Astronomical Society. Although dedicated in 1897, it was founded in 1892.

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 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 , 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 virgin wooded Yerkes land on the lakeshore—the last such undeveloped, natural site on Geneva Lake's 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 Charles Olmsted, the nephew and adopted son of famed landscape architect Frederick Law Olmsted. 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. In May 2018, the Yerkes Future Foundation, a group of local residents, submitted an expression of interest to the University of Chicago with a proposal that would seek to maintain public access to the site and continuation of the educational programs. Transfer of operation to a successor operator was not arranged by the end of August, and the facility was closed to the general public on October 1. Some research activities continued at the Observatory, including access and use of the extensive historical glass plate archives at the site. Yerkes education and outreach staff formed a nonprofit organization – GLAS – to continue their programs at another site after the closing. In May 2019, the university continued to negotiate with interested parties on Yerkes's future, primarily with the Yerkes Future Foundation. It was announced in November 2018 that a sticking point has been the need to include the Yerkes family in the discussions. Mr. Yerkes's agreement in making his donation to the university transfers ownership "To have and to hold unto the said Trustees [of the University of Chicago] and their successors so long as they shall use the same for the purpose of astronomical investigation, but upon their failure to do so, the property hereby conveyed shall revert to the said Charles T. Yerkes or his heirs at law, the same as if this conveyance had never been made." For the closing, there was a new gate with a sign that read "Facilities Closed To The Public" starting October 1, 2018. In 2022, the site was re opened to visitors. In 2023, Amanda Bauer was interviewed and demonstrates the use of the telescope, partly restored. Full restoration was expected to take 10 more years.

The Observatory grounds and buildings are renowned for more than the Great Refractor, but also sculptures and architecture. In addition, the landscaping is also famed for its design work by Olmsted. The observatory building was designed by architect Henry Ives Cobb, and has been referred to as being in the Beaux Arts style. The building is noted for its blend of styles and rich ornamentation featuring a variety of animal and mythological designs. The location is noted for a good and pleasant location by Lake Geneva. In 1888, Williams Bay had a railway terminal added by Chicago & North Western Railroad; this provided access from Chicago, and is one factor that increased the site's development in the following decades. The editorial offices for The Astrophysical Journal were located at Yerkes Observatory until the 1960s. The tree plan design was developed in the 1910s under design from the Olmsted firm and with support of the observatory Director; the grounds included the following types of trees at that time: white fir, yellowwood tree, golden rain tree, European beech, fernleaf beech, Japanese pagoda tree, littleleaf linden, Kentucky coffeetree, ginkgo, cut leaf beeches, and chestnut trees.