The 100 inch (2. 5 m) Hooker reflecting telescope at Mount Wilson Observatory near Los Angeles, California. A reflecting telescope (also called a reflector) is an Optical telescope which uses a single or combination of Curved mirrors that reflect Light The Mount Wilson Observatory (MWO is an Astronomical observatory in Los Angeles County California. Los Angeles (lɑˈsændʒələs los ˈaŋxeles in Spanish) is the largest City in the state of California and the American West

A telescope is an instrument designed for the observation of remote objects and the collection of electromagnetic radiation. Electromagnetic radiation takes the form of self-propagating Waves in a Vacuum or in Matter. The first known practically functioning telescope is credited to the German-Dutch lensmaker Hans Lippershey in 1608. Hans Lippershey (1570&ndashSeptember 1619 also known as Johann Lippershey or Lipperhey, was a German - Dutch lensmaker. The name "Telescope" (from the Greek tele = 'far' and skopein = 'to look or see'; teleskopos = 'far-seeing') was a name given to Galileo Galilei's instrument for viewing distant objects. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly Galileo Galilei (15 February 1564 &ndash 8 January 1642 was a Tuscan ( Italian) Physicist, Mathematician, Astronomer, and Philosopher The name was invented by an unidentified Greek poet/theologian, present at a banquet held in 1611 by Prince Federico Cesi to make Galileo Galilei a member of the Accademia dei Lincei^[1]. Federico Angelo Cesi ( February 26, 1585 Rome - August 1, 1630 Acquasparta) was an Italian Scientist, Galileo Galilei (15 February 1564 &ndash 8 January 1642 was a Tuscan ( Italian) Physicist, Mathematician, Astronomer, and Philosopher The Accademia dei Lincei, (literally the " Academy of the Lynxes" but also known as the Lincean Academy) is an Italian science academy located "Telescope" can refer to a whole range of instruments operating in most regions of the electromagnetic spectrum. The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies

Types of telescopes

The name "telescope" covers a wide range of instruments and is difficult to define. They all have the attribute of collecting electromagnetic radiation so it can be studied or analyzed in some manner. The most common type is the optical telescope. Other types also exist and are listed below.

Optical telescopes

50 cm refracting telescope at Nice Observatory. The Observatoire de Nice ( Nice Observatory) is located in Nice, France on the summit of Mont Gros.

Main article: Optical telescope

An optical telescope gathers and focuses light mainly from the visible part of the Electromagnetic spectrum (although some work in the infrared and ultraviolet). An optical telescope is a Telescope which is used to gather and focus light mainly from the visible part of the Electromagnetic spectrum In Geometrical optics, a focus, also called an image point, is the point where Light rays originating from a point on the object converge. The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays Optical telescopes increase the apparent angular size of distant objects, as well as their apparent brightness. The angular diameter of an object as seen from a given position is the "visual diameter" of the object measured as an angle Brightness is an attribute of Visual perception in which a source appears to emit or reflect a given amount of Light. Telescopes work by employing one or more curved optical elements - usually made from glass - lenses or mirrors - to gather light or other electromagnetic radiation and bring that light or radiation to a focus, where the image can be observed, photographed, studied, or sent to a computer. Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many A lens is an optical device with perfect or approximate Axial symmetry which transmits and refracts Light, converging or diverging A mirror is an object with a surface that has good Specular reflection; that is it is smooth enough to form an Image. In Geometrical optics, a focus, also called an image point, is the point where Light rays originating from a point on the object converge. Optical telescopes are used for astronomy and in many non-astronomical instruments, including: theodolites (including transits), spotting scopes, monoculars, binoculars, camera lenses, and spyglasses. Astronomy (from the Greek words astron (ἄστρον "star" and nomos (νόμος "law" is the scientific study A theodolite ( is an instrument for measuring both horizontal and vertical Angles as used in Triangulation networks A spotting scope is a portable Telescope, optimized for the observation of terrestrial objects A monocular is a modified Refracting telescope used to Magnify the images of distant objects by passing light through a series of lenses and prisms Binocular telescopes, or binoculars (also known as field glasses are two identical or Mirror - symmetrical telescopes mounted side-by-side and A photographic lens (also known as objective lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with There are three main types:

• The refracting telescope which uses lenses to form an image. A refracting or refractor telescope is a dioptric Telescope that uses a lens as its objective to form an image
• The reflecting telescope which uses an arrangement of mirrors form an image. A reflecting telescope (also called a reflector) is an Optical telescope which uses a single or combination of Curved mirrors that reflect Light
• The catadioptric telescope which uses mirrors combined with lenses, in front of the mirror or somewhere within the optical path, to form an image. A catadioptric optical system is one which contains both lenses and Mirrors Catadioptric systems are commonly used in Telescopes and in lightweight

Radio telescopes

Main article: Radio telescope

The Very Large Array at Socorro, New Mexico, United States. A radio telescope is a form of directional Radio antenna used in Radio astronomy and in tracking and collecting data from Satellites The Very Large Array ( VLA) is a Radio astronomy Observatory located on the Plains of San Augustin, between the towns of Magdalena

Radio telescopes are directional radio antennae that often have a parabolic shape. A directional antenna or beam antenna is an antenna which radiates greater power in one or more directions allowing for increased performance on transmit and receive An antenna is a Transducer designed to transmit or Receive electromagnetic waves In other words antennas convert electromagnetic waves into The dishes are sometimes constructed of a conductive wire mesh whose openings are smaller than the wavelength being observed. In Physics wavelength is the distance between repeating units of a propagating Wave of a given Frequency. Multi-element Radio telescopes are constructed from pairs or larger groups of these dishes to synthesize large "virtual" apertures that are similar in size to the separation between the telescopes: see aperture synthesis. A radio telescope is a form of directional Radio antenna used in Radio astronomy and in tracking and collecting data from Satellites As of 2005, the current record array size is many times the width of the Earth, utilizing space-based Very Long Baseline Interferometry (VLBI) telescopes such as the Japanese HALCA (Highly Advanced Laboratory for Communications and Astronomy) VSOP (VLBI Space Observatory Program) satellite. Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 Very Long Baseline Interferometry (VLBI is a type of astronomical interferometry used in Radio astronomy. For a topic outline on this subject see List of basic Japan topics. The HALCA (Highly Advanced Laboratory for Communications and Astronomy, also known as MUSES-B before launch and Haruka after launch is a Japanese owned Aperture synthesis is now also being applied to optical telescopes using optical interferometers (arrays of optical telescopes) and Aperture Masking Interferometry at single reflecting telescopes. Optical interferometry combines two or more light waves in an optical instrument in such a way that Interference occurs between them Radio telescopes are also used to collect microwave radiation, often used to help study the leftover Big Bang radiation, and also can be used to collect radiation when visible light is obstructed or faint, such as from quasars. Microwaves are electromagnetic waves with Wavelengths ranging from 1 mm to 1 m or frequencies between 0 The Big Bang is the cosmological model of the Universe that is best supported by all lines of scientific evidence and Observation. A quasar (contraction of QUASi-stellAR radio source) is an extremely powerful and distant Active galactic nucleus. Some radio telescopes are used by programs such as SETI and the Arecibo Observatory to search for exterrestrial life. Search for Extra-Terrestrial Intelligence ( SETI) is the collective name for a number of activities to detect intelligent Extraterrestrial life. The Arecibo Observatory is a very sensitive Radio telescope located approximately south-southwest from the town of Arecibo in Puerto Rico. (see also: Wow! Signal)

X-ray and gamma-ray telescopes

Main articles: X-ray astronomy and gamma-ray astronomy

X-ray and gamma-ray radiation go through most metals and glasses, some X-ray telescopes use Wolter telescopes composed of ring-shaped "glancing" mirrors, made of heavy metals, that reflect the rays just a few degrees. The Wow ! signal was a strong Narrowband radio signal detected by Dr X-ray astronomy is an observational branch of Astronomy, which deals with the study of X-ray emission from celestial objects Gamma-ray astronomy is the astronomical study of the Cosmos with Gamma rays. X-radiation (composed of X-rays) is a form of Electromagnetic radiation. Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions A mirror is an object with a surface that has good Specular reflection; that is it is smooth enough to form an Image. This article describes the unit of angle For other meanings see Degree. The mirrors are usually a section of a rotated parabola and a hyperbola or ellipse. In Mathematics, the parabola (pəˈræbələ from the Greek παραβολή) is a Conic section, the intersection of a right circular In Geometry, a hyperbola ( Greek, "over-thrown" has several equivalent definitions In Mathematics, an ellipse (from the Greek ἔλλειψις literally absence) is a Conic section, the locus of points in a Gamma-ray telescopes refrain from focusing completely, and use coded aperture masks; the pattern of shadows the mask creates can be reconstructed to form an image.

These types of telescopes are usually on Earth-orbiting satellites or high-flying balloons, since the Earth's atmosphere is opaque to this part of the electromagnetic spectrum. This article is about artificial satellites For natural satellites also known as moons see Natural satellite. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five

A diagram of the electromagnetic spectrum with the Earth's atmospheric transmittance (or opacity) and the types of telescopes used to image parts of the spectrum. The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies

Other types

• Binoculars
• Spotting scopes
• Monoculars
• Telephoto lens
• Solar telescope
• Theodolites

Notable telescopes

• Anglo-Australian Telescope
• Arecibo Observatory
• Atacama Large Millimeter Array
• Chandra X-ray Observatory
• CHARA (Center for High Angular Resolution Astronomy) array
• Giant Metrewave Radio Telescope
• Great Paris Exhibition Telescope of 1900
• Hale telescope
• Hexapod-Telescope
• Hooker Telescope
• Hubble Space Telescope
• IceCube Neutrino Detector
• Isaac Newton Telescope
• Keck telescope
• Lick Observatory
• LIGO
• Lovell Telescope
• McMath-Pierce Solar Telescope
• McMath-Hulbert Observatory (Solar)
• Magdalena Ridge Observatory
• Multiple-Mirror telescope
• Navy Prototype Optical Interferometer
• Overwhelmingly Large Telescope (proposed)
• Parkes Observatory
• Southern African Large Telescope
• Subaru Telescope
• UK Schmidt Telescope
• Very Large Array
• Very Large Telescope
• Westerbork Synthesis Radio Telescope
• William Herschel Telescope
• XMM-Newton

See also

A group of Newtonian Telescopes at Perkins Observatory, Delaware, Ohio

• Amateur telescope making
• Angular resolution
• Aperture synthesis
• ASCOM open standards for computer control of telescopes
• BOOTES
• Depth of field
• Dynameter
• Eyepiece
• First light
• f-number
• History of telescopes
• Keyhole problem
• List of largest optical reflecting telescopes
• List of largest optical refracting telescopes
• Microscope
• Nimrud lens
• Remote Telescope Markup Language
• Robotic telescope
• Space observatory
• Timeline of telescope technology
• Timeline of telescopes, observatories, and observing technology

Notes

References

• Contemporary Astronomy - Second Edition, Jay M. Pasachoff, Saunders Colleges Publishing - 1981, ISBN 0-03-057861-2
• Elliott, Robert S. Binocular telescopes, or binoculars (also known as field glasses are two identical or Mirror - symmetrical telescopes mounted side-by-side and A spotting scope is a portable Telescope, optimized for the observation of terrestrial objects A monocular is a modified Refracting telescope used to Magnify the images of distant objects by passing light through a series of lenses and prisms A solar telescope is a special purpose Optical telescope used to observe the Sun. A theodolite ( is an instrument for measuring both horizontal and vertical Angles as used in Triangulation networks The Anglo-Australian Telescope (AAT is a 39  m equatorially mounted telescope operated by the Anglo-Australian Observatory and situated at the The Arecibo Observatory is a very sensitive Radio telescope located approximately south-southwest from the town of Arecibo in Puerto Rico. The Atacama Large Millimeter/submillimeter Array ( ALMA) is an international Astronomy project that consists of an Astronomical interferometer formed The Chandra X-ray Observatory is a Satellite launched on STS-93 by NASA on July 23, 1999. The CHARA Array is an Optical Astronomical interferometer operated by The Center for High Angular Resolution Astronomy (CHARA of the Georgia Giant Metrewave Radio Telescope (GMRT, located near Pune in India, is the world's largest array of Radio telescopes at metre Wavelengths The Great Paris Exhibition Telescope of 1900, with an objective lens of 1 The Hale Telescope is the largest telescope at the Palomar Observatory, named after astronomer George Ellery Hale. Engineers of the company Vertex in collaboration with astronomers of the Astronomy Department (AIRUB of the Ruhr-Universität Bochum in Germany developed a concept for a revolutionary design of The Mount Wilson Observatory (MWO is an Astronomical observatory in Los Angeles County California. The Hubble Space Telescope ( HST; also known colloquially as "the Hubble" or just "Hubble" is a space telescope that was carried into The IceCube Neutrino Observatory is a Neutrino Telescope currently under construction at the Amundsen-Scott South Pole Station. The Isaac Newton Telescope or INT is a 25 m optical Telescope run by the ING at Roque de los Muchachos Observatory on The W M Keck Observatory is a two-telescope Astronomical observatory at the 4145 meter (13600 ft summit of Mauna Kea in Hawai'i. The Lick Observatory is an astronomical Observatory, owned and operated by the University of California. For the Latvian holiday Ligo see Jāņi. LIGO stands for Laser Interferometer Gravitational-Wave Observatory. The Lovell Telescope is a Radio telescope at Jodrell Bank Observatory, near Goostrey, Cheshire in the north-west of England The McMath-Pierce Solar Telescope is a 16-m f/ 54 solar telescope at Kitt Peak National Observatory in Arizona, USA. The McMath-Hulbert Solar Observatory located in Lake Angelus Michigan is a decommissioned Solar observatory. Interferometer The Magdalena Ridge Observatory Interferometer will consist of an array of up to ten 1 The MMT Observatory (MMTO is an Astronomical observatory on the site of Fred Lawrence Whipple Observatory (IAU The Navy Prototype Optical Interferometer ( NPOI) is an Interferometer operated by the US Naval Observatory, the Naval Research Laboratory See also List of optical telescopes Very Large Telescope Thirty Meter Telescope Giant Magellan The Parkes Observatory is a Radio telescope observatory 20 kilometres north of the town of Parkes, New South Wales, Australia. The Southern African Large Telescope ( SALT) is a ~10 metre (~33 feet diameter Optical telescope, located in the semi-desert region of the Karoo, South Subaru Telescope (In Japanese: すばる望遠鏡 is the 82 Metre flagship telescope of the National Astronomical Observatory of Japan, located in The 12 Metre UK Schmidt Telescope (UKST is operated by the Anglo-Australian Observatory, and located adjacent to the 3 The Very Large Array ( VLA) is a Radio astronomy Observatory located on the Plains of San Augustin, between the towns of Magdalena The Very Large Telescope ( VLT) is a system of four separate Optical telescopes (the Antu telescope, the Kueyen telescope, the Melipal The Westerbork Synthesis Radio Telescope (WSRT (near camp Westerbork, north of the village of Westerbork, Midden-Drenthe, in the northeastern Netherlands The William Herschel Telescope or WHT was first conceived in the late 1960s when the Anglo-Australian Observatory was being designed The XMM-Newton (X-ray Multi-Mirror Mission - Newton is an orbiting X-ray observatory, named in honor of Isaac Newton. Perkins Observatory is an astronomical Observatory in Delaware Ohio. Geography Delaware is located at (40298898 -83072007 The town is located about 24 miles north of Ohio's capital city Columbus, due north along Ohio ( is a Midwestern state of the United States. As part of the Great Lakes region, Ohio has long been a cultural and geographical crossroads The field of amateur telescope making is considered an offshoot of the Amateur astronomy community Angular resolution describes the resolving power of any image forming device such as an optical or Radio telescope, a Microscope, a Camera ASCOM (an abbreviation for AS tronomy C ommon O bject M odel is an open initiative to provide a standard interface to a range of astronomy equipment BOOTES, the B urst O bserver and O ptical T ransient E xploring S ystem is located in Southern Spain and makes use of two sets In Optics, particularly as it relates to Film and Photography, the depth of field (DOF is the portion of a scene that appears sharp in the image A dynameter is an instrument that measures the Magnification of a Telescope. For the device for looking through a camera see Viewfinder. An eyepiece, or ocular lens, is a type of lens that is attached The keyhole problem in the context of Astronomy refers to the difficulty that azimuth-elevation type telescopes or antenna Gimbal systems encounter The following is a list of the largest optical Reflecting telescopes sorted by mirror diameter Here is a list of the largest optical Refracting telescopes sorted by lens diameter and focal length A microscope ( Greek: ( micron) = small + ( skopein) = to look or see is an instrument for viewing objects that are The Nimrud lens is a 3000 year old piece of Rock crystal, which was unearthed by Austen Henry Layard at the palace of Nimrud in what is now Iraq The Remote Telescope Markup Language (RTML is an XML dialect for controlling remote and/or robotic Telescopes It was created by UC Berkeley A robotic telescope is an astronomical Telescope and detector system that makes Observations without the intervention of a Human. A space observatory is any instrument in Outer space which is used for observation of distant planets galaxies and other outer space objects Timeline of Telescope Technology c 2560 BC - c 860 BC - Egyptian artisans polish Rock crystal, Timeline of Telescopes observatories, and observing Technology. Jay Myron Pasachoff (born 1943) is an American Astronomer. Pasachoff is Field Memorial Professor of Astronomy at Williams College and the (1966), Electromagnetics, McGraw-Hill
• Rashed, Roshdi & Régis Morelon (1996), Encyclopedia of the History of Arabic Science, vol. The McGraw-Hill Companies Inc, ( is a Publicly traded corporation headquartered in Rockefeller Center in New York City. The Encyclopedia of the History of Arabic Science is a three-volume Encyclopedia covering the history of Arabic contributions to science, mathematics 1 & 3, Routledge, ISBN 0415124107
• Wade, Nicholas J. Routledge is a publisher of non-fiction academic books and journals & Stanley Finger (2001), "The eye as an optical instrument: from camera obscura to Helmholtz's perspective", Perception 30 (10): 1157-1177

External links

• "The First Telescopes". Part of an exhibit from Cosmic Journey: A History of Scientific Cosmology by the American Institute of Physics
• ESO 100 m telescope
• The Resolution of a Telescope
• Southern African Large Telescope (SALT)
• The Digges telescope of the 1570s
• The Swedish Solar telescope
• History of Refracting Telescope