The Very Large Telescope (VLT) is an astronomical facility operated since 1998 by the European Southern Observatory, located on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each equipped with a primary mirror that measures 8.2 meters in diameter. These optical telescopes, named Antu, Kueyen, Melipal, and Yepun, are generally used separately but can be combined to achieve a very high angular resolution. The VLT array is also complemented by four movable Auxiliary Telescopes (ATs) with 1.8-meter apertures.
Subaru Telescope is the 8.2-metre (320 in) telescope of the National Astronomical Observatory of Japan, located at the Mauna Kea Observatory on Hawaii. It is named after the open star cluster known in English as the Pleiades. It had the largest monolithic primary mirror in the world from its commissioning until the Large Binocular Telescope opened in 2005.
The Large Binocular Telescope (LBT) is an optical telescope for astronomy located on 10,700-foot (3,300 m) Mount Graham, in the Pinaleno Mountains of southeastern Arizona, United States. It is a part of the Mount Graham International Observatory.
The W. M. Keck Observatory is an astronomical observatory with two telescopes at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii. Both telescopes have 10 m (33 ft) aperture primary mirrors, and, when completed in 1993 and 1996, they were the largest optical reflecting telescopes in the world. They have been the third and fourth largest since 2006.
A reflecting telescope is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternative to the refracting telescope which, at that time, was a design that suffered from severe chromatic aberration. Although reflecting telescopes produce other types of optical aberrations, it is a design that allows for very large diameter objectives. Almost all of the major telescopes used in astronomy research are reflectors. Many variant forms are in use and some employ extra optical elements to improve image quality or place the image in a mechanically advantageous position. Since reflecting telescopes use mirrors, the design is sometimes referred to as a catoptric telescope.
The Gran Telescopio Canarias is a 10.4 m (410 in) reflecting telescope located at the Roque de los Muchachos Observatory on the island of La Palma, in the Canary Islands, Spain. It is the world's largest single-aperture optical telescope.
The WIYN Observatory is owned and operated by the WIYN Consortium. Its 3.5-meter telescope is the second largest optical telescope at Kitt Peak National Observatory in Arizona. Most of the capital costs for the observatory were provided by the University of Wisconsin–Madison, Indiana University, and Yale University, while the National Optical Astronomy Observatory (NOAO) provides most of the operating services. The NOAO is an institution of the United States; it is the national optical observatory program and supports a collection of ground-based telescopes at Kitt Peak as well as other locations.
The VLT Survey Telescope (VST) is a telescope located at ESO's Paranal Observatory in the Atacama Desert of northern Chile. It is housed in an enclosure immediately adjacent to the four Very Large Telescope (VLT) Unit Telescopes on the summit of Cerro Paranal. The VST is a wide-field survey telescope with a field of view twice as broad as the full Moon. It is the largest telescope in the world designed to exclusively survey the sky in visible light.
The New Technology Telescope or NTT is a 3.58-metre Ritchey–Chrétien telescope operated by the European Southern Observatory. It began operations in 1989. It is located in Chile at the La Silla Observatory and was an early pioneer in the use of active optics. The telescope and its enclosure were built to a revolutionary design for optimal image quality.
The Galileo National Telescope, is a 3.58-meter Italian telescope, located at the Roque de los Muchachos Observatory on the island of La Palma in the Canary Islands, Spain. The TNG is operated by the "Fundación Galileo Galilei, Fundación Canaria", a non-profit institution, on behalf of the Italian National Institute of Astrophysics (INAF). The telescope saw first light in 1998 and is named after the Italian Renaissance astronomer Galileo Galilei.
The William Herschel Telescope (WHT) is a 4.20-metre (165 in) optical/near-infrared reflecting telescope located at the Roque de los Muchachos Observatory on the island of La Palma in the Canary Islands, Spain. The telescope, which is named after William Herschel, the discoverer of the planet Uranus, is part of the Isaac Newton Group of Telescopes. It is funded by research councils from the United Kingdom, the Netherlands and Spain.
The Wide Field/Planetary Camera (WFPC) was a camera installed on the Hubble Space Telescope launched in April 1990 and operated until December 1993. It was one of the instruments on Hubble at launch, but its functionality was severely impaired by the defects of the main mirror optics which afflicted the telescope. However, it produced uniquely valuable high resolution images of relatively bright astronomical objects, allowing for a number of discoveries to be made by HST even in its aberrated condition.
The Canada–France–Hawaii Telescope (CFHT) is located near the summit of Mauna Kea mountain on Hawaii's Big Island at an altitude of 4,204 meters, part of the Mauna Kea Observatory. Operational since 1979, the telescope is a Prime Focus/Cassegrain configuration with a usable aperture diameter of 3.58 metres (11.7 ft).
The NASA Infrared Telescope Facility is a 3-meter (9.8 ft) telescope optimized for use in infrared astronomy and located at the Mauna Kea Observatory in Hawaii. It was first built to support the Voyager missions and is now the US national facility for infrared astronomy, providing continued support to planetary, solar neighborhood, and deep space applications. The IRTF is operated by the University of Hawaii under a cooperative agreement with NASA. According to the IRTF's time allocation rules, at least 50% of the observing time is devoted to planetary science.
The Southern Astrophysical Research (SOAR) telescope is a modern 4.1-meter (13 ft) aperture optical and near-infrared telescope located on Cerro Pachón, Chile at 2,738 metres (8,983 ft) elevation. It was commissioned in 2003, and is operated by a consortium including the countries of Brazil and Chile, Michigan State University, the Cerro Tololo Inter-American Observatory (CTIO), and the University of North Carolina at Chapel Hill. Partners have guaranteed shares varying from 10 to 30 percent of the observing time.
The Mercator Telescope is a 1.2 m telescope at the Observatorio del Roque de Los Muchachos on La Palma. It is operated by the Katholieke Universiteit Leuven, Belgium, in collaboration with the Observatory of the University of Geneva and named after Gerard Mercator, famous cartographer.
The Vainu Bappu Observatory is an astronomical observatory owned and operated by the Indian Institute of Astrophysics. It is located at Kavalur in the Javadi Hills, near Vaniyambadi in Tirupathur district in the Indian state of Tamil Nadu. It is 200 km south-west of Chennai and 175 km south-east of Bangalore.
The Dunn Solar Telescope, also known as the Richard B. Dunn Solar Telescope, is a unique vertical-axis solar telescope that specializes in high-resolution imaging and spectroscopy. It is located at Sacramento Peak in Sunspot, New Mexico. It is the main telescope at the Sunspot Solar Observatory, operated by New Mexico State University in partnership with the National Solar Observatory through funding from the National Science Foundation, the state of New Mexico, and private funds from other partners. The Dunn Solar Telescope helps astrophysicists worldwide better understand the Sun and how it affects Earth.
The C. Donald Shane telescope is a 120-inch (3.05-meter) reflecting telescope located at the Lick Observatory in San Jose, California. It was named after astronomer C. Donald Shane in 1978, who led the effort to acquire the necessary funds from the California Legislature, and who then oversaw the telescope's construction. It is the largest and most powerful telescope at the Lick Observatory, and was the second-largest optical telescope in the world when it was commissioned in 1959.
The Mount Abu InfraRed Observatory (MIRO) is located near the town Mount Abu in the state of Rajasthan, India. The observatory is at an altitude of 1680 metres and is adjacent to Guru Shikhar, highest peak of the Aravalli Range. The 1.2 m infrared telescope at It is the first major facility in India specifically designed for ground-based, infrared observations of celestial objects. Further the low amount of precipitable water vapour at Guru Shikhar makes it a good site for the infrared telescope observations. The site has been found to be good for astronomical observations.
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