Yerkes Observatory

(redirected from Yerkes refractor)

Yerkes Observatory,

astronomical observatoryobservatory,
scientific facility especially equipped to detect and record naturally occurring scientific phenomena. Although geological and meteorological observatories exist, the term is generally applied to astronomical observatories.
..... Click the link for more information.
 located in Williams Bay, Wis., on the shore of Lake Geneva. It was founded in 1892 with funds provided by Charles T. YerkesYerkes, Charles Tyson
, 1837–1905, American financier, b. Philadelphia. He began his business career as a clerk in a Philadelphia grain commission house. He became a broker in 1858 and prospered, but in 1871 he was convicted of misappropriating city funds and was
..... Click the link for more information.
 and its first director was George E. HaleHale, George Ellery,
1868–1938, American astronomer, b. Chicago, grad. Massachusetts Institute of Technology, 1890. He founded and directed three great observatories (Yerkes, Mt.
..... Click the link for more information.
. The observatory is administered by the Univ. of Chicago. The principal instrument is a 40-in. refracting telescopetelescope,
traditionally, a system of lenses, mirrors, or both, used to gather light from a distant object and form an image of it. Traditional optical telescopes, which are the subject of this article, also are used to magnify objects on earth and in astronomy; other types of
..... Click the link for more information.
, 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.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Yerkes Observatory


a scientific institution of the Uni-versity of Chicago (USA). It was organized in 1892–97, 22 kmfrom Chicago. Its instruments include a 102-cm (40-in.) refrac-tor (the largest in the world, constructed by A. G. Clark andpaid for by C. Yerkes), a 30-cm (12-in.) double refractor, afour-camera astrograph (largest objectives, 25 and 16 cm) witha 13-cm (5-in.) visual refractor, 102-cm (40-in.) and 60-cm(24-in.) reflectors, a Schmidt camera, and a 15-cm (6-in.) comet-finder. Work is conducted at the observatory on solar research, the determination of stellar parallaxes and radial velocities, thestudy of double stars, stellar polarization, stellar photometry, and the photographing of stars and planets. Yerkes Observatoryissues Publications (since 1900).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
But the Yerkes refractor, at 60 feet (18 meters) long and with thick lenses even at f/19, seemed to be near a practical limit.
(30) That same day Edward Emerson Barnard (1857-1923) had the 40-inch (1m) Yerkes refractor pointing at Saturn.
More telling still the reputable American observer Edward Emerson Barnard (1857-1923) examined Saturn and its ring system with the 40-inch Yerkes refractor at Williams Bay, Wisconsin, on the evening of 1909 January 12.
In effect this implies the Yerkes refractor was ill-suited to show a dim feature in close proximity to the bright rings.
Barnard's comments after observing M5's variables with the 40-inch Yerkes refractor in 1898 are also interesting to note:
The completion of the 40-inch Yerkes refractor in 1897 marked the first of four successive times that Hale secured the money to build the world's largest operational telescope.
It was discovered and sketched on April 24, 1900, by Edward Emerson Barnard with the 40-inch Yerkes refractor. IC 4677 has been misclassified as a galaxy in several catalogs.
(The 40-inch Yerkes refractor would require a tube 400 feet long!) The traditional compromise has been to employ focal ratios of f/12 to f/16 and simply tolerate the color error.
In 1897, when the Yerkes refractor was dedicated in the rural town of Williams Bay, Wisconsin, it ranked as the largest operating telescope in the world (see page 26).