Treptow telescope (aka Himmelskanone) did away with a dome, and the telescope tube extends above the building in this imageGrande Lunette of Nice Observatory of 1886, with 76 cm apertureJames Lick telescope of 1888, with 91 cm aperture
Great refractor refers to a large telescope with a lens, usually the largest refractor at an observatory with an equatorial mount. The preeminence and success of this style in observational astronomy defines an era in modern telescopy[1] in the 19th and early 20th century.[1] Great refractors were large refracting telescopes using achromatic lenses (as opposed to the mirrors of reflecting telescopes). They were often the largest in the world, or largest in a region. Despite typical designs having smaller apertures than reflectors, great refractors offered a number of advantages and were popular for astronomy.[1] It was also popular to exhibit large refractors at international exhibits, and examples of this include the Trophy Telescope at the 1851 Great Exhibition, and the Yerkes Great Refractor at the 1893 World's Fair in Chicago.
A great refractor was often the centerpiece of a new 19th century observatory, but was typically used with an entourage of other astronomical instruments such as a Meridian Circle, a Heliometer, an Astrograph, and a smaller refractor such as a Comet Seeker or Equatorial. Great refractors were often used for observing double stars and equipped with a Filar micrometer. Pioneering work on astrophotography was done with great refractors.[2]
An example of prime achievements of refractors, over 7 million people have been able to view through the 12-inch Zeiss refractor at Griffith Observatory since it opened in 1935; this is the most people to have viewed through any telescope.[3] In modern times many large refractors have become important historical items, and are often used for public astronomy outreaches. However, many have also been shut down or moved due to their difficulty of use as telescopes. Whereas in the modern era aperture and location are important, the older style observatories were often located near towns because astronomy was only one function; major tasks were simply to record the weather, make accurate determinations of location, and to determine the local time. In modern times many of these functions are performed elsewhere and communicated locally.
Some noted accomplishments of refractors were the discovery of Neptune, the discovery of the Moons of Mars, and the compilation of various star catalogs. A derivative instrument of refractors, the heliometer was used to measure for the first time the distance to another star by geometric parallax in the mid-1800s. As telescopes became larger and longer, the relatively modest increases in aperture belied their enormous size, with moving weights in the multiple tons in domes several stories tall; physically many of the biggest were larger than even some modern reflecting telescopes.
^ abc"Era: Great Refractors". Amazing-space.stsci.edu. Retrieved 2014-03-01.
^"Harvard College Observatory: Great Refractor". Cfa.harvard.edu. 2012-11-21. Retrieved 2014-03-01.
^"Zeiss Telescopes - Griffith Observatory - Southern California's gateway to the cosmos!".
Greatrefractor refers to a large telescope with a lens, usually the largest refractor at an observatory with an equatorial mount. The preeminence and...
A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens as its objective to form an image (also referred to a...
include the James Lick telescope (91.4), Potsdam GreatRefractor (80+50 cm), and the Greenwich 28 inch refractor (71.1 cm). Institutionally it was part of the...
Observatory in 1926. The Meudon Greatrefractor is the third largest astronomical refractor of its type in the world. The Meudon refractor is located in the Grande...
Potsdam GreatRefractor (Große Refraktor) is an historic astronomical telescope in an observatory in Potsdam, Germany. Completed in 1899, it is a double...
The next largest refractor telescopes are the James Lick telescope, and the Meudon GreatRefractor. Most are classical greatrefractors, which used achromatic...
dome houses a 40 in-diameter (102 cm) doublet lens refracting telescope, the second-largest refractor ever successfully used for astronomy. The largest...
the Harvard College Observatory. HCO's first telescope, the 15-inch GreatRefractor, was installed in 1847. That telescope was the largest in the United...
"Harvard College Observatory: GreatRefractor". www.cfa.harvard.edu. Retrieved September 8, 2019. "Fitz/Clark 12-in Refractor". The General History of Astronomy...
perform checks of Einstein's theory of General Relativity; and the GreatRefractor of Potsdam, which today belong to the Astrophysical Institute Potsdam...
fourth largest in the World. The Observatory also has an old style GreatRefractor (a Großen Refraktor), a long telescope with a lens (60 cm/~23.6 in...
surfaces from the National Observatory of Athens, Pic du Midi, and Meudon GreatRefractor. Jean is responsible for creating the most highly visual map of Mars...
an observatory in Berlin-Treptow. It houses the Großer Refraktor (GreatRefractor), which is the longest pointable telescope in the world. It is also...
Paris inch is the lens measurement of the first greatrefractor telescope, the Dorpat GreatRefractor, also known as the Fraunhofer 9-inch. The 9-Paris...
a limited basis. Also called the "Great Lick Refractor" or simply "Lick Refractor", it was the largest refracting telescope in the world until 1897 and...
capitalize on Voyager's observations. 1904: Astronomers using the Potsdam GreatRefractor with a spectrograph find evidence of the interstellar medium while...
considerable number of "GreatRefractors" were built from 60 cm to 1 metre aperture, culminating in the Yerkes Observatory refractor in 1897; however, starting...
List of largest optical reflecting telescopes List of largest optical refracting telescopes List of optical telescopes List of proposed space observatories...
west of Berlin, though the Einstein Tower solar observatory and the greatrefractor telescope on Telegrafenberg in Potsdam belong to the AIP. The key topics...
on July 16 and 17, 1850 with Harvard College Observatory's 15 inch Greatrefractor. In 1863 the English chemist William Allen Miller and English amateur...
1880s). In the records for the largest refracting telescopes, all three were outperformed by the 91 cm (36 in) refractor installed at the Lick Observatory...
18.5-inch (470 mm) aperture greatrefractor telescope for Dearborn Observatory, which was one of the largest refracting telescope lenses in existence...
is located in Middletown, Connecticut (USA). This has a surviving Greatrefractor, a long telescope with lens popular in the late 1800s, as well as some...
Earth. The technical limit concerning lens sag was reached at the Yerkes refractor (1897) with an aperture of 40" (102 cm), where the sagging already causes...
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