List of largest optical telescopes in Ireland and the United Kingdom is a list of the largest optical telescopes in the British Isles, including in the United Kingdom and Ireland.
The most famous telescopes include Herschel's reflector, with which he discovered Georgium Sidus (the planet Uranus), and the Leviathan of Parsonstown which at 1.83 meters (72 inches) was for decades the largest aperture telescope in the World. In the 20th century many older telescopes are popular tourist attractions, such as at Royal Observatory in Greenwich, London. There are also a number of modest instruments at universities used for various astronomical projects or education.
The largest optical telescope in Britain was the Isaac Newton Telescope which had a 98 inches (2.5 m) mirror; it was located at the Royal Greenwich Observatory, Herstmonceux from 1965 to 1980, but was then relocated to Roque de los Muchachos Observatory on La Palma, Canary Islands.
The list is not really representative of the largest telescopes operated by the United Kingdom or Ireland, which by the 20th century were building large telescopes overseas or in the southern hemisphere for better weather or other reasons.
The following is a non-comprehensive list of optical telescopes currently located in the British Isles with an aperture of 24 inches or greater:
Name | Effective aperture | Type | Location | Operator | First light | Comments |
---|---|---|---|---|---|---|
Rosse Six Foot Telescope (reconstructed) [1] | 72 in (183 cm) | Newtonian reflector | Birr, Leinster, Ireland | Birr Castle | 1999 | Largest optical telescope in Ireland |
38-inch Congo Schmidt [2] | 38 in (96.5 cm) | Reflector | Herstmonceux, East Sussex, England | The Observatory Science Centre | 1960 | Largest optical telescope in UK, but never used due to flawed optics |
James Gregory Telescope [3] | 37 in (94.0 cm) | Cassegrain reflector | St Andrews, Fife, Scotland | University of St Andrews | 1962 | Largest operational optical telescope in the UK |
Cambridge 36-Inch telescope [4] | 36 in (91.4 cm) | Reflector | Cambridge, Cambridgeshire, England | University of Cambridge | 1955 | Largest optical telescope still in use in England |
36-inch Yapp telescope [5] | 36 in (91.4 cm) | Reflector | Herstmonceux, East Sussex, England | The Observatory Science Centre | 1932 | |
Edinburgh 36-inch telescope [6] | 36 in (91.4 cm) | Reflector | Edinburgh, Scotland | Royal Observatory Edinburgh | 1930 | No longer operational |
34-inch Hewitt Camera [7] | 34 in (86.4 cm) | Reflector | Herstmonceux, East Sussex, England | The Observatory Science Centre | 1950s | |
Perren Telescope [8] | 31.5 in (80.0 cm) | Ritchey–Chrétien reflector | Mill Hill, London, England | UCL Observatory | 2019 | |
Thomson/Regan/Owen Reflector | 30 in (76.2 cm) | Reflector | Great Sutton, Cheshire | David Thomson | 2023 | 30 inch F3 telescope on AltAz GOTO mount. Fully homemade including the optics. Fitted with multiple instruments and a high resolution spectrograph |
John Wall refractor [9] | 30 in (76.2 cm) | Refractor | Hanwell, Oxfordshire, England | Hanwell Community Observatory | 1999 | Largest refractor in the British Isles |
30" Dobsonian [10] | 30 in (76.2 cm) | Reflector | Todmorden, West Yorkshire, England | The Astronomy Centre | 1986 | |
Thompson 30-inch Reflector [11] | 30 in (76.2 cm) | Reflector | Herstmonceux, East Sussex, England | The Observatory Science Centre | 1896 | |
Greenwich 28 inch refractor [12] | 28 in (71.1 cm) | Refractor | Greenwich, London, England | Royal Observatory, Greenwich | 1893 | |
Moses Holden Telescope [13] | 27.6 in (70.1 cm) | Reflector | Preston, Lancashire, England | University of Central Lancashire | 2015 | |
Thompson 26-inch Refractor [14] | 26 in (66.0 cm) | Refractor | Herstmonceux, East Sussex, England | The Observatory Science Centre | 1897 | |
24 / 17" Schmidt Camera [15] | 24 in (61.0 cm) | Reflector | Knighton, Powys, Wales | The Spaceguard Centre | 1950 | Largest optical telescope in Wales |
Thornton Telescope [16] | 24 in (61.0 cm) | Reflector | Keele, Staffordshire, England | Keele University | 1975 | |
24" Telescope [17] | 24 in (61.0 cm) | Reflector | Bayfordbury, Hertfordshire, England | University of Hertfordshire | 2021 |
A noted accomplishment of the biggest telescope at the time, Ross's "six foot" leviathan, was the observation of the spiral structure of M51, which was presented at Cambridge in the summer of 1845. [23] Herschel was quite prolific discovering a planet and many moons of the Solar system also with his reflectors.
The Royal Observatory, Greenwich is an observatory situated on a hill in Greenwich Park in south east London, overlooking the River Thames to the north. It played a major role in the history of astronomy and navigation, and because the Prime Meridian passed through it, it gave its name to Greenwich Mean Time, the precursor to today's Coordinated Universal Time (UTC). The ROG has the IAU observatory code of 000, the first in the list. ROG, the National Maritime Museum, the Queen's House and the clipper ship Cutty Sark are collectively designated Royal Museums Greenwich.
A refracting telescope is a type of optical telescope that uses a lens as its objective to form an image. The refracting telescope design was originally used in spyglasses and astronomical telescopes but is also used for long-focus camera lenses. Although large refracting telescopes were very popular in the second half of the 19th century, for most research purposes, the refracting telescope has been superseded by the reflecting telescope, which allows larger apertures. A refractor's magnification is calculated by dividing the focal length of the objective lens by that of the eyepiece.
William Lassell was an English merchant and astronomer. He is remembered for his improvements to the reflecting telescope and his ensuing discoveries of four planetary satellites.
William Parsons, 3rd Earl of Rosse, was an English engineer and astronomer. He built several giant telescopes. His 72-inch telescope, built in 1845 and colloquially known as the "Leviathan of Parsonstown", was the world's largest telescope, in terms of aperture size, until the early 20th century. From April 1807 until February 1841, he was styled as Baron Oxmantown.
The Dominion Astrophysical Observatory, located on Observatory Hill, in Saanich, British Columbia, was completed in 1918 by the Canadian government. The Dominion architect responsible for the building was Edgar Lewis Horwood. The main instrument is the 72-inch-aperture (1.83 m) Plaskett telescope, proposed and designed by John S. Plaskett in 1910 with the support of the International Union for Cooperation in Solar Research.
The Isaac Newton Telescope or INT is a 2.54 m (100 in) optical telescope run by the Isaac Newton Group of Telescopes at Roque de los Muchachos Observatory on La Palma in the Canary Islands since 1984.
Armagh Observatory is an astronomical research institute in Armagh, Northern Ireland. Around 25 astronomers are based at the observatory, studying stellar astrophysics, the Sun, Solar System astronomy and Earth's climate.
Markree Observatory was an astronomical observatory in County Sligo, Ireland. The asteroid 9 Metis was discovered from this observatory in 1848 by Cooper's assistant Andrew Graham using a comet seeker telescope. The observatory was also home to the largest refractor of the early 1830s, which had a 13.3-inch (340 mm) aperture Cauchoix of Paris lens; the largest in the world at that time. The observatory also housed a number of instruments and was operated to varying degrees throughout the 19th century.
Leviathan of Parsonstown, or Rosse six-foot telescope, is a historic reflecting telescope of 72 inches (1.83 m) aperture, which was the largest telescope in the world from 1845 until the construction of the 100-inch (2.5 m) Hooker Telescope in California in 1917. The Rosse six-foot telescope was built by William Parsons, 3rd Earl of Rosse on his estate, Birr Castle, at Parsonstown in Ireland.
Grubb Parsons was a historic manufacturer of telescopes, active in the 19th and 20th centuries. They built numerous large research telescopes, including several that were the largest in the world of their type.
Thomas Grubb was an Irish optician and founder of the Grubb Telescope Company.
The Crossley telescope is a 36-inch (910 mm) reflecting telescope located at Lick Observatory in the U.S. state of California. It was used between 1895 and 2010, and was donated to the observatory by Edward Crossley, its namesake.
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 in the 19th and early 20th century. Great refractors were large refracting telescopes using achromatic lenses. 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. 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.
The Great Melbourne Telescope was built by the Grubb Telescope Company in Dublin, Ireland in 1868, and installed at the Melbourne Observatory in Melbourne, Australia in 1869. In 1945 that Observatory closed and the telescope was sold and moved to the Mount Stromlo Observatory near Canberra. It was rebuilt in the late 1950s. In 2003 the telescope, still in use as an observatory, was severely damaged in a bushfire. About 70% of the components were salvageable; a project to restore the telescope to working condition started in 2013.
The Craig telescope was a large telescope built in the 1850s, and while much larger than previous refracting telescopes, it had some problems that hampered its use. Its unique design and potential caused a great deal of excitement in its day. The telescope was ready in August 1852 and was visited by William Parsons, 3rd Earl of Rosse, famous for the Leviathan of Parsonstown, a reflecting telescope and the largest telescope of this age with a six foot mirror.
The Shuckburgh telescope or Shuckburgh equatorial refracting telescope was a 4.1 inches (10.4 cm) diameter aperture telescope on an equatorial mount completed in 1791 for Sir George Shuckburgh (1751–1804) in Warwickshire, England, and built by British instrument maker Jesse Ramsden (1735–1800). It was transferred to the Royal Observatory, Greenwich in 1811 and the London Science Museum in 1929. Even though it has sometimes not been regarded as particularly successful, its design was influential. It was one of the larger achromatic doublet telescopes at the time, and one of the largest to have an equatorial mount. It was also known as the eastern equatorial for its location.
The Greenwich 28-inch refractor is a telescope at the Royal Observatory, Greenwich, where it was first installed in 1893. It is a 28-inch ( 71 cm) aperture objective lens telescope, otherwise known as a refractor, and was made by the telescope maker Sir Howard Grubb. The achromatic lens was made Grubb from Chance Brothers glass. The mounting is older however and dates to the 1850s, having been designed by Royal Observatory director George Airy and the firm Ransomes and Simms. The telescope is noted for its spherical dome which extends beyond the tower, nicknamed the "onion" dome. Another name for this telescope is "The Great Equatorial" which it shares with the building, which housed an older but smaller telescope previously.
The Sheepshanks Equatorial Telescope was a 6.7-inch (170 mm) aperture refracting telescope installed in 1838 at the Royal Observatory in Greenwich. The telescope was donated to the observatory by the astronomer Richard Sheepshanks. The telescope had a doublet objective lens made by Cauchoix of Paris. Originally it was mounted on a clockwork driven equatorial mounting by the Grubb Telescope Company on a stone pillar.
The Yapp telescope is a 36-inch reflecting telescope of the United Kingdom, now located at the Observatory Science Centre at Herstmonceux.