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Radiation astronomy/Telescopes
[[Image:Brorfelde Schmidt Telescope.jpg|thumb|right|200px|The Schmidt Telescope at the former Brorfelde Observatory is now used by amateur astronomers. Credit: [[commons:User:Moeng|Mogens Engelund]].]]
A '''radiation telescope''' is an instrument designed to collect and focus radiation so as to make distant sources appear nearer.
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==[[Astronomy]]==
[[Image:Mauna Kea observatory.jpg|thumb|left|200px|Sunset over four telescopes of the [[w:Mauna Kea Observatories|Mauna Kea Observatories]] is pictured, from left to right: the [[w:Subaru Telescope|Subaru Telescope]], the twin [[w:W. M. Keck Observatory|Keck I and II telescope]]s, and the [[w:NASA Infrared Telescope Facility|NASA Infrared Telescope Facility]]. Credit: [http://flickr.com/photos/35188692@N00 Alan L].]]
(contracted; show full)
|title=Mauna Kea Telescopes
|url=http://www.ifa.hawaii.edu/mko/telescope_table.shtml
|publisher=Institute for Astronomy – University of Hawaii
|accessdate=August 29, 2010 }}</ref>"<ref name=MaunaKea/>
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==[[Radiation]]==

“In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space.”<ref name=Radiation>{{ cite web
|title=Radiation, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 31,
|year=2012
|url=http://en.wikipedia.org/wiki/Radiation
|accessdate=2012-06-02 }}</ref>

'''Def.''' an action or process of throwing or sending out a traveling ray in a line, beam, or stream of small cross section is called '''radiation'''.

'''Def.''' “[t]he shooting forth of anything from a point or surface, like the diverging rays of light; as, the radiation of heat”<ref name=Radiation>{{ cite web
|title=radiation, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=June 24,
|year=2012
|url=http://en.wiktionary.org/wiki/radiation
|accessdate=2012-07-07 }}</ref> is called '''radiation'''.

Radiation that a particular telescope or a telescope array observes consists of fast moving entities from which information is gathered using spectroscopy, spatial distributions, or temporal distributions. A galaxy cluster that is moving is radiation and an astronomical object to be observed. Entities moving faster than the galaxy such as protons or photons are observables.

==[[Astronomy/Observatories/Astrodesy|Astrodesy]]==

On [[Earth]], telescopes are positioned using [[geodesy]], such fields as surveying, structural geology of the underlying ground, and architecture. The availability of manpower is usually missing for extraterrestrial observatories on the [[Moon]], [[Mars]], or [[Venus]]. On the [[International Space Station]], manpower is often available for instrument control and use.

==[[Instruments]]==
[[Image:MENISCAS 180.jpg|thumb|right|200px|This is an optical telescope that may be used for optical and visual astronomy. Credit: .]]
'''Def.''' “[a]ny instrument used in astronomy for observing distant objects”<ref name=TelescopeWikt>{{ cite web
|title=telescope, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=December 7,
|year=2013
|url=https://en.wiktionary.org/wiki/telescope
|accessdate=2014-01-03 }}</ref> is called a '''telescope'''.

'''Def.''' any "instrument used in [[astronomy]] for observing distant objects (such as a radio telescope)"<ref name=TelescopeWikt/> is called a '''telescope''', or an '''astronomical telescope'''.
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==Aerial telescopes==
[[Image:Aerialtelescope.jpg|thumb|right|200px|An engraving of Huygens 210-foot aerial telescope showing the eyepiece and objective mounts and connecting string. Credit: .]]
“An '''aerial telescope''' is a type of very-long-focal-length [[w:refracting telescope|refracting telescope]] built in the second half of the 17th century that did not use a tube.<ref name=Rice>{{ cite web
|title=The Telescope
|url=http://galileo.rice.edu/sci/instruments/telescope.html
|publisher=The Galileo Project
|accessdate=5 March 2012 }}</ref> Instead, the [[w:Objective (optics)|objective]] was mounted on a pole, tree, tower, building or other structure on a swivel ball-joint. The observer stood on the ground and held the [[w:eyepiece|eyepiece]], which was connected to the objective by a string or connecting rod.  By holding the string tight and maneuvering the eyepiece, the observer could aim the telescope at objects in the sky.”<ref name=AerialTelescope>{{ cite web
|title=Aerial telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=August 16,
|year=2012
|url=http://en.wikipedia.org/wiki/Aerial_telescope
|accessdate=2012-10-08 }}</ref>

“After about 1675, therefore, astronomers did away with the telescope tube. The objective was mounted on a building or pole by means of a ball-joint and aimed by means of a string...”<ref name=Rice/>
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==[[Early telescopes]]==
[[Image:Nimrud lens British Museum.jpg|thumb|right|250px|This image is a photo of the [[w:Nimrud lens|Nimrud lens]] in the [[w:British museum|British museum]]. Credit: [[commons:User:Geni|Geni]].]]
"There are indeed ancient tablets that mention astronomers' lenses supported by a golden tube to enlarge the pupil, and in Nineveh a rock crystal [[w:Nimrud lens|lens]] was found (Pettinato 1998). Maybe one day a new archaeological excavation will find a Babylonian telescope for the first time."<ref name=Magli>{{ cite book
|author=Giulio Magli
|title=When the method is lacking, In: ''Mysteries and Discoveries of Archaeoastronomy from Giza to Easter Island''
|publisher=Copernicus Books
|location=Rome, Italy
|month=
|year=2009
|editor=
|pages=97-116
|url=
|bibcode=
|doi=10.1007/978-0-387-76566-2_5
|pmid=
|isbn=978-0-387-76564-8
|pdf=http://www.springerlink.com/content/w2q6g0q252221k0u/fulltext.pdf
|accessdate=2011-10-15 }}</ref>
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==[[Physics/Optics|Optics]]==

"'''Optics''' involves the behavior and properties of [[w:light|light]], including its interactions with [[w:matter|matter]] and the construction of [[w:optical instruments|instruments]] that use or [[w:Photodetector|detect]] it.<ref name=McGrawHill>{{ cite book
|title=McGraw-Hill Encyclopedia of Science and Technology
|edition=5th
|publisher=McGraw-Hill
|year=1993 }}</ref> Optics usually describes the behavior of [[w:visible light|visible]], [[w:ultraviolet|ultraviolet]], and [[w:infrared|infrared]] light. Because light is an [[w:electromagnetic wave|electromagnetic wave]], other forms of [[w:electromagnetic radiation|electromagnetic radiation]] such as [[w:X-ray|X-ray]]s, [[w:microwave|microwave]]s, and [[w:radio wave|radio wave]]s exhibit similar properties.<ref name=McGrawHill />"<ref name=Optics>{{ cite web
|title=Optics, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=July 1,
|year=2012
|url=http://en.wikipedia.org/wiki/Optics
|accessdate=2012-07-07 }}</ref>

==[[Radiation astronomy/Colors|Colors]]==

"[B]roadband optical photometry of Centaurs and Kuiper Belt objects from the Keck 10 m, the University of Hawaii 2.2 m, and the Cerro Tololo InterAmerican (CTIO) 1.5 m telescopes [shows] a wide dispersion in the optical colors of the objects, indicating nonuniform surface properties. The color dispersion [may] be understood in the context of the expected steady reddening due to bombardment by the ubiquitous flux of cosmic rays."<ref name=Luu>{{ cite journal
|author=Jane Luu and David Jewitt
|title=Color Diversity among the Centaurs and Kuiper Belt Objects
|journal=The Astronomical Journal
|month=November
|year=1996
|volume=112
|issue=5
|pages=2310-8
|url=http://adsabs.harvard.edu/full/1996AJ....112.2310L
|arxiv=
|bibcode=1996AJ....112.2310L
|doi=
|pmid=
|accessdate=2013-11-05 }}</ref>

==[[Minerals]]==
[[Image:Transparency.jpg|thumb|right|200px|This shows a colorless and very clean quartz that is transparent. Credit: [[commons:User:Zimbres|Zimbres]].]]
(contracted; show full)|location=San Francisco, California
|month=June 26,
|year=2012
|url=http://en.wikipedia.org/wiki/Ultraviolet
|accessdate=2012-06-26 }}</ref>
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==Theoretical radiation astronomy telescopy==

'''Def.''' "[t]he manufacture and use of telescopes"<ref name=TelescopyWikt>{{ cite web
|title=telescopy, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=April 1,
|year=2013
|url=http://en.wiktionary.org/wiki/telescopy
|accessdate=2013-07-21 }}</ref> is called '''telescopy'''.

'''Def.''' "[t]he manufacture and use of radio telescopes"<ref name=RadiotelescopyWikt>{{ cite web
|title=radiotelescopy, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=April 2,
|year=2013
|url=http://en.wiktionary.org/wiki/radiotelescopy
|accessdate=2013-07-21 }}</ref> is called '''radiotelescopy'''.

==[[Astronomy/Sources|Sources]]==
[[Image:Horizontal cyclotron with glowing beam.jpg|thumb|center|300px|This image shows a beam of accelerated ions (perhaps protons or deuterons) escaping the accelerator and ionizing the surrounding air causing a blue glow. Credit: Lawrence Berkely National Laboratory.]]
[[Image:Synchrotron light.jpeg|thumb|right|200px|The image shows the blue glow given off by the synchrotron beam from the National Synchrotron Light Source. Credit: NSLS, Brookhaven National Laboratory.]]
The image above shows a blue glow in the surrounding air from emitted cyclotron particulate radiation.

At right is an image that shows the blue glow resulting from a beam of relativistic electrons as they slow down. This deceleration produces synchrotron light out of the beam line of the National Synchrotron Light Source.
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==[[Radiation astronomy/Bands|Bands]]==
[[Image:Rosetta.jpg|thumb|right|200px|This is a 3D model of the Rosetta Spacecraft. The individual scientific payloads are highlighted in different colours. Credit: [[w:User:IanShazell|IanShazell]].]]
For elongated dust particles in cometary comas an investigation is performed at 535.0 nm (green) and 627.4 nm (red) peak transmission wavelengths of the [[w:Rosetta (spacecraft)|Rosetta spacecraft]]'s OSIRIS Wide Angle Camera broadband green and red filters, respectively.<ref name=Bertini>{{ cite journal
|author=I. Bertini, N. Thomas, and C. Barbieri
|title=Modeling of the light scattering properties of cometary dust using fractal aggregates
|journal=Astronomy & Astrophysics
|month=January
|year=2007
|volume=461
|issue=1
|pages=351-64
|url=http://www.aanda.org/articles/aa/full/2007/01/aa5461-06/aa5461-06.html
|arxiv=
|bibcode=2007A&A...461..351B
|doi=10.1051/0004-6361:20065461
|pmid=
|pdf=http://www.aanda.org/articles/aa/pdf/2007/01/aa5461-06.pdf
|accessdate=2011-12-08 }}</ref>
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==[[Astronomy/Backgrounds|Backgrounds]]==
[[Image:Red-blue-noise.gif|frame|The frame demonstrates an example of visual snow-like noise. Credit: .]]
"In astronomical [[w:Charge-coupled device|CCD]] technology, '''background''' is usually referred to the overall optical "noise" of the system, that is, the incoming light on the CCD sensor in absence of light sources. This background can originate from electronic noise in the CCD, from not-well-masked lights nearby the telescope, and so on. An exposure on an empty patch of the sky is also called a background, and is the sum of the system background level plus the sky's one."<ref name=BackgroundAstronomy/>

"A '''background frame''' is often the first exposure in an astronomical observation with a CCD: the frame will then be subtracted from the actual observation result, leaving in theory only the incoming light from the astronomical object being observed."<ref name=BackgroundAstronomy>{{ cite web
|title=Background (astronomy), In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=October 7,
|year=2010
|url=http://en.wikipedia.org/wiki/Background_(astronomy)
|accessdate=2013-05-03 }}</ref>
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==[[Instruments/Telescopes/Meteors|Meteor telescopes]]==
[[Image:250mm Rain Gauge.jpg|thumb|upright|left|125 px|The image shows a standard rain gauge. Credit: .]]
Meteor telescopes per se are often other types of telescopes, such as optical telescopes, that happen or are slewed to observe meteors.

At left is a collection device for rain on [[Earth]] as part of [[meteorology]].

There are favorable locations on Earth, Moon and Mars where [[meteorites]] are discovered. These meteorite, or micrometeorite, locations include Antarctica and the equatorial deserts.
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==[[Instruments/Telescopes/Cosmic rays|Cosmic-ray telescopes]]==
[[Image:HEAO-3.gif|thumb|right|200px|This is an image of HEAO 3. Credit: .]]
[[Image:Pioneer 10-11 - P52a - fx.jpg|thumb|left|150px|The charged particle instrument (CPI) is used to detect cosmic rays in the solar system. Credit: NASA.]]
[[Image:Pioneer 10-11 - P52b - fx.jpg|thumb|left|150px|The cosmic-ray telescope collects data on the composition of the cosmic ray particles and their energy ranges. Credit: NASA.]]
(contracted; show full)|arxiv=
|bibcode=1974ApJ...187L.105M
|doi=10.1086/181407
|pmid=
|accessdate=2012-12-05 }}</ref>
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==[[Instruments/Telescopes/Neutrons|Neutron telescopes]]==
[[Image:Comptel.png|thumb|left|200px|The Imaging Compton Telescope (COMPTEL) utilizes the Compton Effect and two layers of gamma-ray detectors. Credit: NASA.]]
(contracted; show full)|location=Greenbelt, Maryland USA
|month=November
|year=1996
|url=http://heasarc.gsfc.nasa.gov/docs/cgro/nra/appendix_g.html#III.%20COMPTEL%20GUEST%20INVESTIGATOR%20PROGRAM
|accessdate=2013-04-05 }}</ref>
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==[[Instruments/Telescopes/Electrons|Electron telescopes]]==
[[Image:Galileo Energetic Particles Detector.jpg|thumb|right|200px|This is an image of the Energetic Particles Detector (EPD) aboard the Galileo Orbiter. Credit: NASA.]]
"[The] two bi-directional, solid-state detector telescopes [of the Galileo Orbiter are] mounted on a platform which [is] rotated by a stepper motor into one of eight positions. This rotation of the platform, combined with the spinning of the orbiter in a plane perpendicular to the platform rotation, [permits] a 4-pi [or 4π] steradian coverage of incoming [electrons]. The forward (0 degree) ends of the two telescopes [have] an unobstructed view over the [4π] sphere or [can] be positioned behind a shield which not only [prevents] the entrance of incoming radiation, but [contains] a source, thus allowing background corrections and in-flight calibrations to be made. ... The 0 degree end of the [Low-Energy Magnetospheric Measurements System] LEMMS [uses] magnetic deflection to separate incoming electrons and ions. The 180 degree end [uses] absorbers in combination with the detectors to provide measurements of higher-energy electrons ... The LEMMS [provides] measurements of electrons from 15 keV to greater than 11 MeV ... in 32 rate channels."<ref name=Williams>{{ cite web
|author=Donald J. Williams
|title=Energetic Particles Detector (EPD)
|publisher=NASA Goddard Space Flight Center
|location=Greenbelt, Maryland USA
|month=May 14,
|year=2012
|url=http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1989-084B-06
|accessdate=2012-08-11 }}</ref>
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==[[Instruments/Telescopes/Positrons|Positron telescopes]]==
[[Image:509305main GBM positron event 300dpi.jpg|thumb|right|200px|Observation of positrons from a terrestrial gamma ray flash is performed by the Fermi gamma ray telescope. Credit: NASA Goddard Space Flight Center.]]
The image at right contains a picture of the Fermi gamma-ray telescope that performed observations of positrons from their terrestrial gamma-ray flashes.

The positrons are not directly observed by the INTEGRAL space telescope, but "the 511 keV positron annihilation emission is".<ref name= Weidenspointner >{{ cite journal
|author=G. Weidenspointner, G.K. Skinner, P. Jean, J. Knödlseder, P. von Ballmoos, R. Diehl, A. Strong, B. Cordier, S. Schanne, C. Winkler
|title=Positron astronomy with SPI/INTEGRAL
|journal=New Astronomy Reviews
|month=October
|year=2008
|volume=52
|issue=7-10
|pages=454-6
|url=http://www.sciencedirect.com/science/article/pii/S1387647308001164
|arxiv=
|bibcode=
|doi=10.1016/j.newar.2008.06.019
|pmid=
|accessdate=2011-11-25 }}</ref>
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==[[Instruments/Telescopes/Neutrinos|Neutrinos telescopes]]==
[[Image:Antares Neutrinoteleskop.jpg|thumb|right|250px|An artist illustration of the Antares neutrino detector and the [[w:Nautile|Nautile]]. Credit: .]]
[[Image:Icecube-architecture-diagram2009.PNG|thumb|left|200px|This is an architecture diagram of IceCube. Credit: [[w:User:Nasa-verve|Nasa-verve]].]]
(contracted; show full)|location=San Francisco, California
|month=August 10,
|year=2012
|url=http://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory
|accessdate=2012-08-23 }}</ref>
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==[[Instruments/Telescopes/Gamma rays|Gamma-ray telescopes]]==
[[Image:Comptel.png|thumb|left|200px|The Imaging Compton Telescope (COMPTEL) utilizes the Compton Effect and two layers of gamma-ray detectors. Credit: NASA.]]
[[Image:GLAST on the payload attach fitting.jpg|thumb|right|200px|The Fermi Gamma-ray Space Telescope sits on its payload attachment fitting. Credit: NASA/Kim Shiflett.]]
(contracted; show full)|year=2012
|url=http://physicsworld.com/cws/article/news/2012/may/09/silicon-prism-bends-gamma-rays
|accessdate=2013-05-09 }}</ref>

"Materials with nuclei that have a large positive charge – such as gold – should be ideal for making gamma-ray lenses".<ref name=Wogan/>
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==[[Instruments/Telescopes/X-rays|X-ray telescopes]]==
[[Image:Xrtlayout.gif|thumb|right|200px|The XRT uses a grazing incidence Wolter 1 telescope to focus X-rays onto a state-of-the-art CCD. Credit: .]]
"X-ray telescopes can use a variety of different designs to image X-rays. The most common methods used in X-ray telescopes are grazing incidence mirrors and coded apertures. The limitations of X-ray optics result in much narrower fields of view than visible or UV telescopes."<ref name=Xraytelescope>{{ cite web
(contracted; show full)|location=San Francisco, California
|month=February 20,
|year=2012
|url=http://en.wikipedia.org/wiki/Wolter_telescope
|accessdate=2012-06-15 }}</ref>
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==[[Instruments/Telescopes/Opticals|Optical telescopes]]==
[[Image:HST-SM4.jpeg|thumb|right|200px|The Hubble Space Telescope is seen from the departing Space Shuttle Atlantis, flying Servicing Mission 4 (STS-125), the fifth and final human spaceflight to visit the observatory. Credit: Ruffnax (Crew of STS-125).]]
[[Image:HaleTelescope-MountPalomar.jpg|thumb|left|200px|Mt.Palomar's 200-inch Telescope, pointing to the zenith, is seen from the east side. Note the person standing below the telescope (center-right at the bottom of the image). Credit: NASA.]]
(contracted; show full)|year=2013
|url=http://en.wikipedia.org/wiki/Hubble_Space_Telescope
|accessdate=2013-01-22 }}</ref>

Most radiation telescopes, especially optical telescopes, combine a variety of lenses, mirrors, active and adaptive optics, filters, detectors, mounts, image processing, and observatories, in many locations.
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==[[Physics/Optics/Actives|Active optics]]==
[[Image:GTC Active Optics Acutators.jpg|thumb|right|200px|Actuators are part of the active optics of the ''[[w:Gran Telescopio Canarias|Gran Telescopio Canarias]]''. Credit: .]]
“'''Active optics''' is a [[w:technology|technology]] used with [[w:reflecting telescope|reflecting telescope]]s developed in the 1980s<ref name=Hardy>{{ cite journal
|author=John W. Hardy
|title=Active optics: A new technology for the control of light
|year=1977
|month=June
(contracted; show full)|location=San Francisco, California
|month=12 October
|year=2014
|url=http://en.wikipedia.org/wiki/Active_optics
|accessdate=2014-12-25 }}</ref>
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==[[Physics/Optics/Adaptives|Adaptive optics]]==
[[Image:GRAAL instrument.jpg|thumb|right|200px|This image shows some of the GRAAL instrument team inspecting GRAAL’s mechanical assembly. Credit: ESO.]]
'''Def.''' "[a]n optical system in telescopes that reduces atmospheric distortion by dynamically measuring and correcting wavefront aberrations in real time, often by using a deformable mirror"<ref name=AdaptiveOpticsWikt>{{ cite web
|title=adaptive optics, In: ''Wiktionary''
(contracted; show full)improve the quality of images by compensating for turbulence in the lower layers of the atmosphere, up to an altitude of 1 kilometre. GRAAL, which will be installed on ESO’s Very Large Telescope (VLT) on Cerro Paranal in Chile, is designed to improve the vision of the VLT’s already excellent HAWK-I camera even further. Currently, HAWK-I operates without adaptive optics. Installing GRAAL will improve the sharpness of HAWK-I’s images, and reduce the exposure times needed by up to a factor of two.
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==[[Instruments/Telescopes/Refracting|Refracting telescopes]]==
[[Image:Kepschem.png|thumb|right|200px|This is a schematic of a Keplerian refracting telescope which uses two different sizes of planoconvex lenses. Credit: .]]
"The '''Keplerian Telescope''', invented by [[w:Johannes Kepler|Johannes Kepler]] in 1611, is an improvement on Galileo's design.<ref name=Tunnacliffe>{{ cite book
|title= Optics
|author= AH Tunnacliffe, JG Hirst
|year= 1996
|publisher= 
|location= Kent, England 
(contracted; show full)ive]] [[w:lens (optics)|lens]] '''1''' and some type of [[w:eyepiece|eyepiece]] '''2''' is used to gather more light than the human eye could collect on its own, focus it '''5''', and present the viewer with a [[w:brightness|brighter]], [[w:clarity|clearer]], and [[w:magnification|magnified]] [[w:virtual image|virtual image]] '''6'''."<ref name=RefractingTelescope/>
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==[[Instruments/Telescopes/Reflecting|Reflecting telescopes]]==
[[Image:SOFIA 2.5M Primary Mirror.jpg|thumb|left|200px|The [[NASA]] logo on Bldg. 703 at the Dryden Aircraft Operations Facility in Palmdale, California, is reflected in the 2.5 m primary mirror of the SOFIA observatory's telescope. Credit: .]]
[[Image:Franklin reflector 24.jpg|right|thumb|200px|24 inch convertible Newtonian/Cassegrain reflecting telescopeis shown on display at the [[w:Franklin Institute|Franklin Institute]]. Credit: .]]
"A '''reflecting telescope''' (also called a '''reflector''') is an [[w:optical telescope|optical telescope]] which uses a single or combination of [[w:curved mirror|curved mirror]]s that reflect [[w:light|light]] and form an [[w:image|image]]."<ref name=ReflectingTelescope>{{ cite web
|title=Reflecting telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=July 2,
|year=2012
|url=http://en.wikipedia.org/wiki/Reflecting_telescope
|accessdate=2012-07-07 }}</ref>
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==[[Instruments/Telescopes/Catadioptrics|Catadioptric telescopes]]==

'''Def.''' “optical systems that employ both refractive (dioptric) and reflective (catoptric) elements”<ref name=CatadioptricWikt>{{ cite web
|title=catadioptric, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=9 October
|year=2013
|url=https://en.wiktionary.org/wiki/catadioptric
|accessdate=2014-12-25 }}</ref> are called '''catadioptric optical systems'''.

'''Def.''' “[t]he construction and use of catadioptric lenses and systems”<ref name=CatadioptricsWikt>{{ cite web
|title=catadioptrics, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=9 October
|year=2013
|url=https://en.wiktionary.org/wiki/catadioptrics
|accessdate=2014-12-25 }}</ref> is called '''catadioptrics'''.

==[[Instruments/Telescopes/Dobsonians|Dobsonian telescopes]]==
[[Image:Red dobsonian.jpg|thumb|right|200px|This is a red Dobsonian telescope on display at Stellafane in the early 1980s. Credit: .]] 
"A '''Dobsonian telescope''' is an alt-azimuth mounted newtonian telescope design popularized by the [amateur astronomy] John Dobson starting in the 1960s. Dobson's telescopes featured a simplified mechanical design that was easy to manufacture from readily available components to create a large, portable, low-cost telescope. The design is optimized for visually observing faint deep sky objects such as nebulae. This type of observation requires a large objective diameter (i.e. light-gathering power) of relatively short focal length and portability for travel to relatively less light polluted locations.<ref name="books.google.com">[http://books.google.com/books?id=l2TNnHkdDpkC&pg=PA286&lr=#PPA287,M1 Jack Newton, Philip Teece - "'''The Guide to Amateur Astronomy'''" - Page 287]</ref><ref>[http://books.google.com/books?id=9gUjaCMlX5oC&pg=PA37&dq=dobsonian+amateur+telescope+makers&lr= Timothy Ferris "'''Seeing in the Dark'''" - Page 39]</ref>"<ref name=DobsonianTelescope>{{ cite web
|title=Dobsonian telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=December 20,
|year=2013
|url=https://en.wikipedia.org/wiki/Dobsonian_telescope
|accessdate=2014-01-03 }}</ref>
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==[[Instruments/Telescopes/Schmidt|Schmidt telescopes]]==
[[Image:Schmidt telescope (PSF).svg|thumb|200px|right|The diagram illustrates the optical ray paths inside a Schmidt telescope. Credit: .]]
[[Image:Alfred-Jensch-Teleskop.jpg|thumb|200px|left|The 2 meter diameter (Alfred-Jensch-Telescope at the Karl Schwarzschild Observatory in Tautenburg, Thuringia, Germany, is the largest '''Schmidt camera''' in the world. Credit: .]]
At the top of this lecture/article is the Schmidt Telescope at the former Brorfelde Observatory. It is now used by amateur astronomers. The telescope from 1966 is still located in the same building in Brorfelde as originally. Today the telescope has a 77 cm mirror and a digital 2048x2048 pixel CCD-camera. Originally photographic film was used, and in the lower right part an engineer is showing the former film-box, which was then placed behind the locker at the center of the telescope (at the prime focus).

"A '''Schmidt camera''', also referred to as the '''Schmidt telescope''', is a catadioptric astrophotographic [optical] telescope designed to provide wide fields of view with limited aberrations."<ref name=SchmidtCamera>{{ cite web
|title=Schmidt camera, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=December 30,
|year=2013
|url=https://en.wikipedia.org/wiki/Schmidt_camera
|accessdate=2014-01-03 }}</ref>
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==[[Instruments/Telescopes/Maksutovs|Maksutov telescopes]]==
[[Image:Maksutov 150mm.jpg|right|thumb|200px|A 150mm aperture Maksutov–Cassegrain telescope is shown. Credit: .]]
[[Image:Maksutov spot cassegrain.png|right|thumb|200px|Light path in a typical "Gregory" or "spot" Maksutov–Cassegrain is diagrammed. Credit: .]]
"The '''Maksutov''' is a catadioptric telescope design that combines a spherical mirror with a  weakly negative meniscus lens in a design that takes advantage of all the surfaces being nearly "spherically symmetrical".<ref name=Savard>{{ cite web
|author=John J. G. Savard
|title='Miscellaneous Musings
|url=http://www.quadibloc.com/science/opt0203.htm }}</ref> The negative lens is usually full diameter and placed at the entrance pupil of the telescope (commonly called a "corrector plate" or "meniscus corrector shell"). The design corrects the problems of off-axis aberrations such as coma found in reflecting telescopes while also correcting chromatic aberration."<ref name=MaksutovTelescope>{{ cite web
|title=Maksutov telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=December 9,
|year=2013
|url=https://en.wikipedia.org/wiki/Maksutov_telescope
|accessdate=2014-01-03 }}</ref>
{{clear}}

==[[Instruments/Telescopes/Ultraviolets|Ultraviolet telescopes]]==

"The Extreme ultraviolet Imaging Telescope (EIT) is an instrument on the [[w:Solar and Heliospheric Observatory|SOHO]] spacecraft used to obtain high-resolution images of the solar corona in the ultraviolet range. The EIT instrument is sensitive to light of four different wavelengths: 17.1, 19.5, 28.4, and 30.4 nm, corresponding to light produced by highly ionized iron (XI)/(X), (XII), (XV), and helium (II), respectively. EIT is built as a single telescope with a quadrant structure to the entrance mi(contracted; show full)

"The multilayer technology allows conventional telescope forms (such as the Cassegrain or Ritchey-Chretien designs) to be used in a novel part of the spectrum."<ref name=ExtremeUltravioletImagingTelescope/>


==[[Instruments/Telescopes/Visuals|Visual telescopes]]==
[[Image:USNO Refractor 1904.jpg|thumb|right|200px|This image shows the 26-inch Warner & Swasey refracting telescope at the United States Naval Observatory. Credit: Waldon Fawcett.]]
“I think everyone can conjure up a mental image of astronomers at every level and place in history, gazing through the eyepieces of their telescopes at sights far away - true visual astronomy.”<ref name=Cooke>{{ cite book
|author=Antony Cooke
|title=Visual Astronomy Under Dark Skies: A New Approach to Observing Deep Space
|publisher=Springer-Verlag
|location=London
|month=
|year=2005
|editor=
|pages=180
|url=http://books.google.com/books?id=SXmrBfl4H3sC&dq=entity+astronomy&lr=&source=gbs_navlinks_s
|bibcode=
|doi=
|pmid=
|isbn=1852339012
|accessdate=2011-11-06 }}</ref>
{{clear}}

==[[Filters/Astronomy|Astronomical filters]]==
[[Image:Dichroic filters.jpg|thumb|right|200px|[[w:Ultraviolet|Ultraviolet]] filters are used in astronomy for blocking this part of the spectrum, which causes the camera to heat up when photographing without affecting the image. Credit: .]]
(contracted; show full)|location=San Francisco, California
|month=July 18,
|year=2012
|url=http://en.wikipedia.org/wiki/Astronomical_filter
|accessdate=2012-07-29 }}</ref>
{{clear}}


==[[Instruments/Telescopes/Infrareds|Infrared telescopes]]==
[[Image:Spitzer- Telescopio.jpg|thumb|right|200px|The image shows the Spitzer Space Telescope prior to launch. Credit: NASA/JPL/Caltech.]]
[[Image:Diagram Reflector RitcheyChretien.svg|thumb|right|200px|The diagram is  of a Ritchey-Chrétien reflector telescope. Credit: .]]
[[Image:NOFS 40inch03.jpg|thumb|left|200px|This is an early Ritchey-Chrétien reflector telescope. Credit: P. Shankland.]]
(contracted; show full)

The telescope at left is the early Ritchey–Chrétien 1.0 meter telescope at NOFS at the [[w:United States Naval Observatory Flagstaff Station|United States Naval Observatory Flagstaff Station]].


==[[Instruments/Telescopes/Submillimeters|Submillimeter telescopes]]==
[[Image:Caltech-Submillimeter-Observatory (straightened).jpg|thumb|right|200px|This photograph shows the 10.4-metre diameter submillimeter wavelength telescope of the Caltech Submillimeter Observatory (CSO). Credit: [http://www.flickr.com/people/62472689@N00 Samuel Bouchard] from Quebec City, Canada; modified by [[commons:User:Huntster|Huntster]].]]
(contracted; show full)|location=San Francisco, California
|month=May 5,
|year=2012
|url=http://en.wikipedia.org/wiki/Heinrich_Hertz_Submillimeter_Telescope
|accessdate=2012-08-04 }}</ref>
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==[[Instruments/Telescopes/Radios|Radio telescopes]]==
[[Image:parkes.arp.750pix.jpg|thumb|right|200px|This 64 meter radio telescope is at [[w:Parkes Observatory|Parkes Observatory]] Credit: John Sarkissian (CSIRO Parkes Observatory).]]
'''Def.''' “[a] device for studying astronomical sources of radio waves”<ref name=RadioTelescopeWikt>{{ cite web
|author=[[wikt:User:SemperBlotto|SemperBlotto]]
|title=radio telescope, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
(contracted; show full)|location=San Francisco, California
|month=29 January
|year=2015
|url=https://en.wikipedia.org/wiki/Radio_telescope
|accessdate=2015-02-03 }}</ref>
{{clear}}


==[[Instruments/Telescopes/Microwaves|Microwave telescopes]]==
[[Image:RTEmagicC Planck satellite 01.jpg|thumb|right|200px|The Planck telescope was launched in 2009 to observe the Cosmic Microwave Background Radiation. Credit: ESA.]]
"The basic scientific goal of the Planck mission is to measure [cosmic microwave background] CMB anisotropies at all angular scales larger than 10 arcminutes over the entire sky with a precision of ~2 parts per million. The model payload consists of a 1.5 meter off-axis telescope with two focal plane arrays of detectors sharing the focal plane. Low frequencies will be covered by 56 tuned radio receivers sensitive to 30-100 GHz, while high frequencies will be covered by 56 bolometers sensitive to 100-850 GHz."<ref name=Chuss>{{ cite web
|author=David T. Chuss
|title=The Planck Mission
|publisher=Goddard Space Flight Center
|location=Greenbelt, Maryland USA
|month=April 18,
|year=2008
|url=http://lambda.gsfc.nasa.gov/product/space/p_overview.cfm
|accessdate=2013-12-12 }}</ref>
{{clear}}

==[[Instruments/Telescopes/Radars|Radar telescopes]]==
[[Image:ADU-1000-3.jpg|thumb|200px|right|This image shows the early planetary radar at [[w:Pluton (complex)|Pluton]], USSR, 1960. Credit: [[commons:User:Rumlin|Rumlin]].]]
[[Image:Arecibo Observatory Aerial View.jpg|thumb|left|200px|The Arecibo Radio Telescope, Arecibo, Puerto Rico, at 1000 feet (305 m) across, is the largest dish antenna in the world. Credit: H. Schweiker/WIYN and NOAO/AURA/NSF, NOAA.]]
(contracted; show full)|accessdate=2012-12-09 }}</ref>

At second lower left is the Evpatoria RT-70 radar telescope in the Ukraine.

At lower right is an artist's impression of the two radar satellites TerraSAR-X and TanDEM-X.
{{clear}}


==[[Instruments/Interferometers/Radios|Radio interferometry]]==
[[Image:Interf diagram.gif|thumb|right|200px|The diagram shows a possible layout for an astronomical interferometer, with the mirrors laid out in a parabolic arrangement (similar to the shape of a conventional telescope mirror). Credit: .]]
(contracted; show full)|closure phase]] to combine telescopes separated by thousands of kilometers to form a radio interferometer with the resolution which would be given by a single dish which was thousands of kilometers in diameter. ... Astronomical interferometers can produce higher [[w:Angular resolution|resolution]] astronomical images than any other type of telescope. At radio wavelengths image resolutions of a few micro-[[w:arcsecond|arcsecond]]s have been obtained”<ref name=AstronomicalInterferometer/>.
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==[[Instruments/Telescopes/Superluminals|Superluminal telescopes]]==

"The Cherenkov telescopes do not actually detect the gamma rays directly but instead detect the flashes of visible light [Cherenkov radiation] produced when gamma rays are absorbed by the Earth's atmosphere.<ref name=Penston>{{ cite web
|author = Margaret J. Penston
|date = 14 August 2002
|url=http://www.pparc.ac.uk/frontiers/latest/feature.asp?article=14F1&style=feature
|title = The electromagnetic spectrum
|publisher = Particle Physics and Astronomy Research Council
|accessdate = 17 August 2006 }}</ref>"<ref name=Astronomy>{{ cite web
|title=Astronomy, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=July 19,
|year=2012
|url=http://en.wikipedia.org/wiki/Astronomy
|accessdate=2012-07-28 }}</ref>

==[[Instruments/Telescopes/Plasma objects|Plasma-object telescopes]]==
[[Image:HallThruster 2.jpg|thumb|2 kW Hall thruster is in operation as part of the Hall Thruster Experiment at the Princeton Plasma Physics Laboratory. Credit: [[w:User:Dstaack|Dstaack]].]]
[[Image:Xenon hall thruster.jpg|thumb|This is a xenon 6 kW Hall thruster in operation at the NASA Jet Propulsion Laboratory. Credit: NASA/JPL-Caltech.]]
(contracted; show full)|year=2013
|url=http://en.wikipedia.org/wiki/Hall_effect_thruster
|accessdate=2013-05-28 }}</ref>

While these thrusters are not plasma-object telescopes, they may serve to maneuver or slew a space telescope. As sources of blue light they mat serve as calibrated light sources.
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==[[Instruments/Telescopes/Gaseous objects|Gaseous-object telescopes]]==
[[Image:Sun Gun.jpg|thumb|right|200px|This is an image of a Sun Gun Telescope. Credit: .]]
The "'''Sun Gun Telescope''' [is] designed so that large groups of people can view the [[Sun (star)|sun]] safely - in particular it was created as a way to encourage children to become interested in [[astronomy]].  With this safe and portable device, both amateur science enthusiasts and professionals alike can observe sun spots."<ref name=SunGunTelescope>{{ cite web
|title=Sun Gun Telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=December 2,
|year=2013
|url=https://en.wikipedia.org/wiki/Sun_Gun_Telescope
|accessdate=2014-01-03 }}</ref>

The "Sun Gun [has] a 60mm dia. 900mm fl. optical tube which is mounted inside a 3" PVC which is in turn connected to a 20" plastic flower planter. A rear projection screen is ... mounted on the top of the flower planter. The entire Sun Gun can be made from items easily found at most local hardware stores. The scope itself is an inexpensive 60mm refractor available from many sources."<ref name=SunGunTelescope/>
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==[[Instruments/Telescopes/Liquid objects|Liquid-object telescopes]]==
[[Image:Liquid Mirror Telescope.jpg|thumb|right|This is a liquid mirror telescope. Credit: .]]
"'''Liquid mirror telescopes''' are telescopes with mirrors made with a reflective liquid. The most common liquid used is mercury, but other liquids will work as well (for example, low melting alloys of gallium). The container for the liquid is rotating so that the liquid assumes a paraboloidal shape. A paraboloidal shape is precisely the shape needed for the primary mirror of a telescope. The rotating liquid assumes the paraboloidal shape regardless of the container's shape. To reduce the amount of liquid metal needed, and thus weight, a rotating mercury mirror uses a container that is as close to the necessary parabolic shape as possible. Liquid mirrors can be a low cost alternative to conventional large telescopes. Compared to a solid glass mirror that must be cast, ground, and polished, a rotating liquid metal mirror is much less expensive to manufacture."<ref name=LiquidMirrorTelescope>{{ cite web
|title=Liquid mirror telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=October 1,
|year=2013
|url=https://en.wikipedia.org/wiki/Liquid_mirror_telescope
|accessdate=2014-01-03 }}</ref>

A "telescope with a liquid metal mirror can only be used [as a] zenith telescope that looks straight up".<ref name=LiquidMirrorTelescope/>
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==[[Instruments/Telescopes/Hydrogens|Hydrogen telescopes]]==
[[Image:Solarborg.jpg|right|thumb|200px|Here is an example of an amateur solar telescope equipped with a hydrogen-alpha filter system. Credit: .]]
"In the field of [[amateur astronomy]] ... Amateurs use ... hydrogen-alpha filter systems".<ref name=SolarTelescope>{{ cite web
|title=Solar telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=December 30,
|year=2013
|url=https://en.wikipedia.org/wiki/Solar_telescope
|accessdate=2014-01-03 }}</ref>
{{clear}}

==[[Chemicals/Alloys|Alloys]]==
[[Image:Cloudcroft Observatory.jpg|thumb|right|200px|The image shows the dome of the NASA Orbital Debris Observatory near Cloudcroft, New Mexico. Credit: NASA.]]
[[Image:CCD_Debris_Telescope.png|thumb|left|200px|This image shows the CCD Debris Telescope that is under the NODO dome. Credit: ]]
"The NASA-LMT was 3 m (9.8 ft) aperture liquid mirror telescope located in NODO's main dome. It consisted of a 3 m diameter parabolic dish that held 4 U.S. gallons (15 l) of a highly reflective liquid metal, mercury, spinning at a rate of 10 rpm, with sensors mounted above on a fixed structure. Due to the primary mirror's material, the NASA-LMT was configured as a zenith telescope. Using 20 narrowband filters, it cataloged space debris in Earth's orbit."<ref name=NASAOrbitalDebrisObservatory>{{ cite web
|title=NASA Orbital Debris Observatory, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 6,
|year=2013
|url=https://en.wikipedia.org/wiki/NASA_Orbital_Debris_Observatory
|accessdate=2014-01-03 }}</ref>

"The 32 cm (13 in) CCD Debris Telescope (CDT) was a portable Schmidt camera equipped with a 512×512 pixel charge-coupled device (CCD) sensor. It operated at NODO from October of 1997 until December of 2001, and was used to characterize debris at or near geosynchronous orbit."<ref name=NASAOrbitalDebrisObservatory/>
{{clear}}

==[[Rocks/Meteorites|Meteorites]]==
[[Image:Carancas Meteorite 2.jpg|thumb|right|200px|The image contains a 27.70 g fragment of the Carancas meteorite fall. The scale cube is 1 cm<sup>3</sup>. Credit: Meteorite Recon.]]
"On September 20, the X-Ray Laboratory at the Faculty of Geological Sciences, Mayor de San Andres University, [[w:La Paz, Bolivia|La Paz, Bolivia]], published a report of their analysis of a small sample of material recovered from the impact site. They detected iron, nickel, cobalt, and traces of iridium &mdash; elements characteristic of the elemental composition of meteorites. The quantitative proportions of silicon, aluminum, potassium, calcium, magnesium, and phosphorus are incompatible with rocks that are normally found at the surface of the Earth.<ref name=Blanco>Mario Blanco Cazas, [http://fcpn.umsa.bo/fcpn/app?service=external/PublicationDownload&sp=227 "Informe Laboratorio de Rayos X &mdash; FRX-DRX"] (in Spanish), Universidad Mayor de San Andres, Facultad de Ciencias Geologicas, Instituto de Investigaciones Geologicas y del Medio Ambiente, La Paz, Bolivia, September 20, 2007. Retrieved October 10, 2007.</ref>"<ref name=2007CarancasImpactEvent>{{ cite web
|title=2007 Carancas impact event, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=April 26,
|year=2013
|url=http://en.wikipedia.org/wiki/2007_Carancas_impact_event
|accessdate=2013-05-12 }}</ref>
{{clear}}

==[[Astronomy/Observatories/Shelters|Shelters]]==

"Telescope domes have a slit or other opening in the roof that can be opened during observing, and closed when the telescope is not in use. In most cases, the entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes usually do not have domes."<ref name=Observatory>{{ cite web
|title=Observatory, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=January 26,
|year=2013
|url=http://en.wikipedia.org/wiki/Observatory
|accessdate=2013-02-05 }}</ref>

==[[Radiation astronomy/Spectroscopy|Spectroscopy]]==

"'''Astronomical spectroscopy''' is the technique of [[w:spectroscopy|spectroscopy]] used in [[astronomy]]. The object of study is the [[w:electromagnetic spectrum|spectrum]] of [[w:electromagnetic radiation|electromagnetic radiation]], including visible light, which [[w:radiant energy|radiates]] from [[w:star|star]]s and other celestial objects.  Spectroscopy can be used to derive many properties of distant stars and galaxies, such as their chemical composition, but also their motion by [[w:Doppler shift|Doppler shift]] measurements."<ref name=AstronomicalSpectroscopy>{{ cite web
|title=Astronomical spectroscopy, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=December 8,
|year=2012
|url=http://en.wikipedia.org/wiki/Astronomical_spectroscopy
|accessdate=2013-01-09 }}</ref>

==[[Radiation astronomy/Spectrometers|Spectrometers]]==
[[Image:Osse.gif|thumb|right|200px|The Oriented Scintillation Spectrometer Experiment (OSSE) consists of four NaI scintillation detectors, sensitive to energies from 50 keV to 10 MeV. Credit: NASA GSFC.]]
"The Oriented Scintillation Spectrometer Experiment (OSSE) will conduct a broad range of observations in the 0.05-250 MeV energy range. Major emphasis is placed on scientific objectives in the 0.1-10.0 MeV region with a limited capability above 10 MeV, primarily for observations of solar gamma-rays and neutrons and observations of high-energy emission from pulsars."<ref name=Johnson>{{ cite web
|author=W. N. Johnson
|title=Appendix G to the NASA RESEARCH ANNOUNCEMENT for the COMPTON GAMMA RAY OBSERVATORY GUEST INVESTIGATOR PROGRAM
|publisher=National Aeronautics and Space Administration Goddard Space Flight Center
|location=Greenbelt, Maryland USA
|month=November
|year=1996
|url=http://heasarc.gsfc.nasa.gov/docs/cgro/nra/appendix_g.html#III.%20COMPTEL%20GUEST%20INVESTIGATOR%20PROGRAM
|accessdate=2013-04-05 }}</ref>
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==[[Instruments/Telescopes/Planetary|Planetary telescopes]]==
[[Image:Goto telescope.jpg|thumb|right|A telescope on an alt-azimuth GoTo mount.  Note the keypad, resting on the platform between the tripod's legs, that is the telescope's hand control.  Batteries are stored in the circular compartment just above the tripod.  In this picture, the compartment is just above the hand control.]]
"In [[amateur astronomy]], "'''GoTo'''" refers to a type of [[telescope mount]] and related [[software]] which can automatically point a telescope to [[astronomical objects]] that the user selects. Both axes of a GoTo mount are motor driven and are controlled by either a microprocessor-based integrated controller or a personal computer, as opposed to the single axis semi-automated tracking of a traditional clock drive mount. This allows the user to command the mount to point the telescope to a right ascension and declination that the user inputs or have the mount itself point the telescope to objects in a pre-programmed data base including ones from the Messier catalogue, the New General Catalogue, and even major solar system bodies (the Sun, Moon, and planets)."<ref name=GoToTelescopes>{{ cite web
|title=GoTo (telescopes), In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 27.
|year=2013
|url=https://en.wikipedia.org/wiki/GoTo_(telescopes)
|accessdate=2014-01-03 }}</ref>
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==[[Instruments/Telescopes/Solar|Solar telescopes]]==
[[Image:Kitt Peak McMath-Pierce Solar Telescope.jpg|thumb|right|200px|This view is of the McMath-Pierce Solar Telescope at Kitt Peak National Observatory, near Tucson, Arizona. Credit: [http://www.flickr.com/photos/oceanyamaha/ ocean yamaha].]]
"A '''solar telescope''' is a special purpose [[w:telescope|telescope]] used to observe the [[Sun (star)|Sun]]. Solar telescopes usually detect light with wavelengths in, or not far outside, the [[w:visible spectrum|visible spectrum]]."<ref name=SolarTelescope>{{ cite web
|title=Solar telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 31,
|year=2012
|url=http://en.wikipedia.org/wiki/Solar_telescope
|accessdate=2012-07-07 }}</ref>
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==[[Instruments/Telescopes/Asteroids|Asteroid telescopes]]==
[[Image:Lowell astrograph.jpg|thumb|200px|right|The Lowell astrograph is a dedicated astrophotography telescope. Credit: .]]
The Lowell astrograph imaged at right is a 13-inch, f/5.3 astrograph at Lowell Observatory,  a refractor with a 3 element Cooke triplet lens.<ref name=Tombaugh>{{ cite web
|author=Clyde W. Tombaugh
|title=The Struggles to Find the Ninth Planet
|url=http://ircamera.as.arizona.edu/NatSci102/NatSci102/text/ext9thplanet.htm }}</ref>) that was used in the discovery of [[Pluto]].

"An '''astrograph''' ('''astrographic camera''') is a telescope designed for the sole purpose of astrophotography. Astrographs are usually used in wide field surveys of the night sky as well as detection of objects such as [[asteroids]], [[meteor]]s, and [[comet]]s."<ref name=Astrograph>{{ cite web
|title=Astrograph, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=December 12,
|year=2013
|url=https://en.wikipedia.org/wiki/Astrograph
|accessdate=2014-01-03 }}</ref>
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==[[Instruments/Telescopes/Comet seekers|Comet-seeker telescopes]]==

"A comet seeker is a type of small telescope adapted especially to searching for comets: commonly of short focal length and large aperture, in order to secure the greatest brilliancy of light."<ref name=CometSeeker>{{ cite web
|title=Comet seeker, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=March 6,
|year=2013
|url=https://en.wikipedia.org/wiki/Comet_seeker
|accessdate=2014-01-03 }}</ref>

==[[Instruments/Telescopes/Stars|Stellar telescopes]]==
[[File:FASTT Transit Circle.jpg|thumb|right|200px|The Ron Stone/Flagstaff Astrometric Scanning Transit Telescope of the U.S.Naval Observatory, built by Farrand Optical Company, 1981, is imaged. Credit: .]]
(contracted; show full)|first2=David G.
|last2=Monet
|year=1990
|journal=Proceedings of IAU Symposium No. 141
|pages=369–370 }}</ref>"<ref name=MeridianCircle/>
{{clear}}


==[[Instruments/Telescopes/Galaxies|Galactic telescopes]]==
[[Image:NGC 891 HST.jpg|thumb|right|200px|NGC 891 is selected as first light. Credit: NASA.]]
[[Image:LargeBinoTelescope NASA.jpg|thumb|left|200px|This is an image of the Large Binocular Telescope with protective doors open. Credit: NASA.]]
The Large Binocular Telescope [at left] is "located on Mount Graham (10,700-foot (3,300 m)) in the Pinaleno Mountains of southeastern Arizona, and is a part of the Mount Graham International Observatory."<ref name=LargeBinocularTelescope>{{ cite web
|title=Large Binocular Telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=May 21,
|year=2013
|url=http://en.wikipedia.org/wiki/Large_Binocular_Telescope
|accessdate=2013-07-02 }}</ref>

"The first image taken [shown at right] combined ultraviolet and green light, and emphasizes the clumpy regions of newly formed hot stars in the spiral arms."<ref name=LargeBinocularTelescope/>
{{clear}}

==[[Geography/Earth/Locations|Locations on Earth]]==
[[Image:VERITAS array.jpg|thumb|right|300px|VERITAS is located at the basecamp of the Smithsonian Astrophysics Observatory's Fred Lawrence Whipple Observatory (FLWO) in southern Arizona. Credit: VERITAS.]]
[[Image:Aerial View of the VLTI with Tunnels Superimposed.jpg|200px|thumb|left|The four Unit Telescopes form the VLT together with the Auxiliary Telescopes. Credit: .]]
(contracted; show full)|location=San Francisco, California
|month=June 17,
|year=2013
|url=http://en.wikipedia.org/wiki/Very_Large_Telescope
|accessdate=2013-07-02 }}</ref>
{{clear}}


==[[History/Recent|Recent history]]==
[[Image:TransitCircle USNO.jpg|thumb|right|200px|This is the 6-inch transit circle of the U.S. Naval Observatory. Credit: .]]
The '''recent history''' period dates from around 1,000 b2k to present.

The 6-inch transit circle [imaged at right] of the U.S. Naval Observatory was built by Warner and Swasey in 1898.
{{clear}}

==[[Radiation astronomy/Telescopes/Apertures|Coded apertures]]==

"Some X-ray telescopes use coded aperture imaging. This technique uses a flat aperture grille in front of the detector, which weighs much less than any kind of focusing X-ray lens, but requires considerably more post-processing to produce an image."<ref name=XRayTelescope>{{ cite web
|title=X-ray telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=April 17,
|year=2012
|url=http://en.wikipedia.org/wiki/X-ray_telescope
|accessdate=2012-06-15 }}</ref>

==[[Radiation astronomy/Telescopes/Mirrors|Mirrors]]==
[[Image:Wolter-types.gif|thumb|right|200px|This is a diagram of Wolter telescopes of Types I, II, and III. Credit: .]]
"The mirrors can be made of ceramic or metal foil.<ref name=xraysMirror>{{ cite web |title=Mirror Laboratory |url=http://astrophysics.gsfc.nasa.gov/xrays/MirrorLab/xoptics.html }}</ref> The most commonly used grazing angle incidence materials for X-ray mirrors are [[w:gold|gold]] and [[w:iridium|iridium]]. The critical reflection angle is energy dependent. For gold at 1&am(contracted; show full)|location=San Francisco, California
|month=June 10,
|year=2012
|url=http://en.wikipedia.org/wiki/History_of_the_telescope
|accessdate=2012-06-26 }}</ref>
{{clear}}


==[[Radiation astronomy/Telescopes/Modulation collimators|Modulation collimators]]==
[[Image:Four-wire grid modulation collimator.jpeg|thumb|right|200px|The diagram shows the principles of operation of the four-grid modulation collimator. Credit: H. Bradt, G. Garmire, M. Oda, G. Spada, and B.V. Sreekantan, P. Gorenstein and H. Gursky.]]
A modulation collimator consists of “two or more wire grids [diffraction gratings] placed in front of an X-ray sensitive Geiger tube or proportional counter.”<ref name=Bradt>{{ cite journal
|author=H. Bradt, G. Garmire, M. Oda, G. Spada, and B.V. Sreekantan, P. Gorenstein and H. Gursky
|title=The Modulation Collimator in X-ray Astronomy
|journal=Space Science Reviews
|month=September
|year=1968
|volume=8
|issue=4
|pages=471-506
|url=
|arxiv=
|bibcode=1968SSRv....8..471B
|doi=10.1007/BF00175003
|pmid=
|accessdate=2011-12-10 }}</ref> Relative to the path of incident X-rays (incoming X-rays) the wire grids are placed one beneath the other with a slight offset that produces a shadow of the upper grid over part of the lower grid.<ref name=Oda>{{ cite journal
|author=Minoru Oda
|title=High-Resolution X-Ray Collimator with Broad Field of View for Astronomical Use
|journal=Applied Optics
|month=January
|year=1965
|volume=4
|issue=1
|pages=143
|url=http://www.opticsinfobase.org/abstract.cfm?URI=ao-4-1-143
|arxiv=
|bibcode=1965ApOpt...4..143O
|doi=10.1364/AO.4.000143
|pmid=
|pdf=http://www.opticsinfobase.org/ao/viewmedia.cfm?uri=ao-4-1-143&seq=0
|accessdate=2011-12-10 }}</ref>
{{clear}}

==[[Computers]]==
[[Image:Lights glowing on the ALMA correlator.jpg|thumb|right|200px|The ALMA correlator is one of the most powerful supercomputers in the world. Credit: ALMA (ESO/NAOJ/NRAO), S. Argandoña.]]
"The ALMA correlator [shown at right], one of the most powerful supercomputers in the world, has now been fully installed and tested at its remote, high altitude site in the Andes of northern Chile. This view shows lights glowing on some of the racks of the correlator in the ALMA Array Operations Site Techical Building. This photograph shows one of the four quadrants of the correlator. The full system has four identical quadrants, with over 134 million processors, performing up to 17 quadrillion operations per second."<ref name=ALMAObservatory>{{ cite web
|author=ALMA Observatory
|title=Lights glowing on the ALMA correlator
|publisher=ALMA Observatory Organization
|location=Atacama, chile
|month=July 10,
|year=2013
|url=http://www.almaobservatory.org/en/visuals/images/the-alma-observatory/?g2_itemId=3939
|accessdate=2013-07-21 }}</ref>
{{clear}}

==[[Instruments/Telescopes/Mounts|Telescope mounts]]==

“A telescope mount is a mechanical structure which supports a telescope. Telescope mounts are designed to support the mass of the telescope and allow for accurate pointing of the instrument.”<ref name=Telescope>{{ cite web
|title=Telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=July 4,
|year=2012
|url=http://en.wikipedia.org/wiki/Telescope
|accessdate=2012-07-07 }}</ref>

'''Def.''' “an object on which another object”<ref name=Mount>{{ cite web
|title=mount, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=June 8,
|year=2012
|url=http://en.wiktionary.org/wiki/mount
|accessdate=2012-07-07 }}</ref> is attached for support is called a '''mount'''.

==Altazimuth mounts==
[[Image:heliostat.jpg|right|200px|thumb|A [[w:heliostat|heliostat]] is shown at the THÉMIS experimental station in France. The mirror rotates on an alt-azimuth mount. The pointing direction of the mirror is perpendicular to its surface. Credit: .]]
(contracted; show full)/ref> is sometimes used to add a third "polar axis" to overcome these problems, providing an hour or more of motion in the direction of [[w:right ascension|right ascension]] to allow for astronomical tracking. The design also does not allow for the use of mechanical [[w:setting circles|setting circles]] to locate astronomical objects although modern [[w:Setting circles#Digital setting circles|digital setting circles]] have removed this shortcoming.”<ref name=AltazimuthMount/>
{{clear}}


==Equatorial mounts==
[[Image:Stuetzmontierung.jpg|thumb|right|200px|An example of an equatorial mount is photographed. Credit: Peter Rucks.]]
“The equatorial mount has north-south "polar axis" tilted to be parallel to Earth's polar axis that allows the telescope to swing in an east-west arc, with a second axis perpendicular to that to allow the telescope to swing in a north-south arc. Slewing or mechanically driving the mounts polar axis in a counter direction to the Earth's rotation allows the telescope to accurately follow the motion of the night sky.”<ref name=TelescopeMount>{{ cite web
|title=Telescope mount, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=21 September
|year=2014
|url=https://en.wikipedia.org/wiki/Telescope_mount
|accessdate=2015-02-03 }}</ref>
{{clear}}

==Hexapod mounts==
[[Image:DOT main mirror.jpg|thumb|right|200px|This is an image of the top part of the Dutch Open Telescope. Credit: Tim van Werkhoven.]]
“Instead of the classical mounting using two axles, the mirror is supported by six extendable struts (hexapod). This configuration allows moving the telescope in all six spatial degrees of freedom and also provides a strong structural integrity.”<ref name=TelescopeMount/>
{{clear}}

==[[Clocks/Drives|Clock drives]]==
[[Image:Aldershot observatory 02.JPG|thumb|right|200px|The clock drive mechanism in the pier of the german equatorial mount for the 8-inch refracting telescope at [[w:Aldershot Observatory|Aldershot Observatory]] is shown in the image. Credit: .]]
(contracted; show full)|location=San Francisco, California
|month=May 30,
|year=2012
|url=http://en.wikipedia.org/wiki/Clock_drive
|accessdate=2012-07-07 }}</ref>
{{clear}}


==[[Clocks]]==
[[Image:FOCS-1.jpg|thumb|left|200px| The FOCS 1 is a continuous cold caesium fountain atomic clock in Switzerland. Credit: .]]
"An '''atomic clock''' is a [[w:clock|clock]] device that uses an [[w:electronic transition|electronic transition]] [[w:frequency|frequency]] in the [[w:microwave|microwave]], [[w:light|optical]], or [[w:ultraviolet|ultraviolet]] region<ref name=McCarthy>{{ cite book
|title=TIME from Earth Rotation to Atomic Physics
(contracted; show full)|year=2012
|url=http://en.wikipedia.org/wiki/Atomic_clock
|accessdate=2012-10-24 }}</ref>

The FOCS 1 continuous cold cesium fountain atomic clock started operating in 2004 at an uncertainty of one second in 30 million years. The clock is in Switzerland.
{{clear}}


==[[Motion calibrators]]==

"'''POA CALFOS''' is the improved Post Operational Archive version of the [[w:Faint Object Spectrograph|Faint Object Spectrograph]] (FOS) calibration pipeline ... The current version corrects for image motion problems that have led to significant wavelength scale uncertainties in the FOS data archive. The improvements in the calibration enhance the scientific value of the data in the FOS archive, making it a more homogeneous and reliable resource."<ref name=POACALFOS>{{ cite web
|title=POA CALFOS, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=July 22
|year=2012
|url=http://en.wikipedia.org/wiki/POA_CALFOS
|accessdate=2012-12-23 }}</ref>

==[[Radiation astronomy/Detectors|Detectors]]==
[[Image:Proportional Counter Array RXTE.jpg|thumb|right|200px|This is an image of a real X-ray detector. The instrument is called the Proportional Counter Array and it is on the [[w:Rossi X-ray Timing Explorer|Rossi X-ray Timing Explorer]] (RXTE) satellite. Credit: .]]
"[[Radiation detectors]] provide a signal that is converted to an electric current. The device is designed so that the current provided is proportional to the characteristics of the incident radiation."<ref name=RadiationDetectors>{{ cite web
|title=Radiation detectors, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=June 19,
|year=2012
|url=http://en.wikiversity.org/wiki/Radiation_detectors
|accessdate=2012-07-07 }}</ref>

Detectors such as the X-ray detector at right collect individual X-rays (photons of X-ray light), count them, discern the energy or wavelength, or how fast they are detected. The detector and telescope system can be designed to yield temporal, spatial, or spectral information.
{{clear}}

==[[Instruments/Telescopes/Image processors|Image processors]]==

'''Def.''' “[a]ny form of information processing for which both the input and output are images”, after Wiktionary [[wikt:image processing|image processing]], is called '''image processing'''.

'''Def.''' “[a] representation of anything ... upon canvas, paper, or other surface”, after Wiktionary [[wikt:picture|picture]], is called a '''picture'''.

(contracted; show full) | title = Principles of Optics
  | publisher = Cambridge University Press
  | date = October 1999
  | location = Cambridge
  | page = 461
  | isbn = 0-521-64222-1}}</ref>"<ref name=AngularResolution/>


==[[Instruments/Telescopes/Robotics|Robotic telescopes]]==
[[Image:El Enano robotic telescope.jpg|thumb|right|200px|“El Enano” is a robotic telescope. Credit: .]]
"A '''robotic telescope''' is an astronomical telescope and detector system that makes observations without the intervention of a human. In astronomical disciplines, a telescope qualifies as robotic if it makes those observations without being operated by a human, even if a human has to initiate the observations at the beginning of the night, or end them in the morning. A robotic telescope is distinct from a remote telescope, though an instrument can be both robotic and remote."<ref name=RoboticTelescope>{{ cite web
|title=Robotic telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=July 1,
|year=2013
|url=https://en.wikipedia.org/wiki/Robotic_telescope
|accessdate=2014-01-03 }}</ref>
{{clear}}

==[[Instruments/Telescopes/Spotting|Spotting telescopes]]==
[[Image:Yukon spotting scope.jpg|thumb|right|200px|This is a 100 mm spotting scope with a coaxial 30 mm finderscope. Credit: .]]
"A '''spotting scope''' is a small portable [[telescope]] with added optics to present an [[erect image]], optimized for the observation of terrestrial objects."<ref name=SpottingScope>{{ cite web
|title=article title, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=February 28,
|year=2013
|url=https://en.wikipedia.org/wiki/Spotting_scope
|accessdate=2014-01-03 }}</ref>

"The light-gathering power and [angular] resolution of a spotting scope is determined by the diameter of the objective lens, typically between 50 and 80 mm. The larger the objective, the more massive and expensive the telescope."<ref name=SpottingScope/>

"The optical assembly has a small refracting objective lens, an image erecting system that uses either image erecting relay lenses or prisms (porro prisms or roof prisms), and an eyepiece that is usually removable and interchangeable to give different magnifications. Other telescope designs are used such as Schmidt and Maksutov optical assemblies. They may have a ruggedised design, a mounting for attaching to a tripod, and an ergonomically designed and located knob for focus control."<ref name=SpottingScope/>
{{clear}}

==[[Astronomy/Observatories|Observatories]]==
[[Image:Champaign-Urbana area IMG 1138.jpg|right|thumb|200px|This equatorial room is at the University of Illinois Observatory. Credit: .]]
"Historically, observatories [are] as simple as [using or placing stably] an astronomical sextant (for measuring the distance between stars) or Stonehenge (which has some alignments on astronomical phenomena). ... Most optical telescopes are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a sli(contracted; show full)|location=San Francisco, California
|month=May 14,
|year=2012
|url=http://en.wikipedia.org/wiki/Equatorial_room
|accessdate=2012-07-07 }}</ref>
{{clear}}


==[[Lofting technology]]==

Many devices for lofting technology have been developed to improve [[radiation astronomy]].

==[[Astronomy/Balloons|Balloons]]==
[[Image:BLAST on flightline kiruna 2005.jpeg|thumb|right|200px|BLAST is hanging from the launch vehicle in [[w:Esrange|Esrange]] near [[w:Kiruna|Kiruna]], [[w:Sweden|Sweden]] before launch June 2005. Credit: [[commons:User:Mtruch|Mtruch]].]]
(contracted; show full)|location=McMurdo Station
|month=December 26,
|year=2012
|url=http://news.yahoo.com/nasa-launches-telescope-toting-balloon-antarctica-christmas-164200686.html
|accessdate=2012-12-26 }}</ref>
{{clear}}


==[[Astronomy/Airborne/Launches|Aircraft assisted launches]]==

"The '''Array of Low Energy X-ray Imaging Sensors''' ('''ALEXIS''') [[X-ray astronomy|X-ray]] telescopes feature curved mirrors whose multilayer coatings reflect and focus low-energy X-rays or extreme ultraviolet light the way [[w:optical telescope|optical telescope]]s focus visible light. ... The Launch was provided by the [[w:United States Air Force|United States Air Force]] Space Test Program on a [[w:Pegasus rocket|Pegasus]] Booster on April 25, 1993.<ref name=ALEXIA>{{ cite web
|title=ALEXIS satellite marks fifth anniversary of launch
|url=http://www.fas.org/spp/military/program/masint/98-062.html
|accessdate=17 August 2011
|publisher=Los Alamos National Laboratory
|date=23 April 1998 }}</ref>"<ref name=ALEXIS>{{ cite web
|title=Array of Low Energy X-ray Imaging Sensors, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=December 18,
|year=2011
|url=http://en.wikipedia.org/wiki/Array_of_Low_Energy_X-ray_Imaging_Sensors
|accessdate=2012-12-09 }}</ref>

==[[Research]]==

Hypothesis:
# Ancients had and used telescopes.

===[[Control groups]]===
[[Image:Lewis rat.jpg|thumb|right|200px|This is an image of a Lewis rat. Credit: Charles River Laboratories.]]
The findings demonstrate a statistically systematic change from the ''status quo'' or the control group.

“In the design of experiments, treatments [or special properties or characteristics] are applied to [or observed in] experimental units in the '''treatment group'''(s).<ref name=Hinkelmann>{{ cite book
(contracted; show full)# collimators, or lenses, to concentrate radiation,
# moderators, to systematically reduce the incoming radiation so as to allow determination of incoming direction,
# detectors, or sensors, to convert the incoming radiation into electrical impulses,
# amplifiers, or processors, and
# supports, to provide orientation and stability of all components.
{{clear}}

==
=[[Proof of concept]]===

'''Def.''' a “short and/or incomplete realization of a certain method or idea to demonstrate its feasibility"<ref name=ProofofConceptWikt>{{ cite web
|title=proof of concept, In: ''Wiktionary''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=November 10,
|year=2012
|url=http://en.wiktionary.org/wiki/proof_of_concept
|accessdate=2013-01-13 }}</ref> is called a '''proof of concept'''.

'''Def.''' evidence that demonstrates that a concept is possible is called '''proof of concept'''.

The proof-of-concept structure consists of
# background,
# procedures,
# findings, and
# interpretation.<ref name=Lehrman>{{ cite journal
|author=Ginger Lehrman and Ian B Hogue, Sarah Palmer, Cheryl Jennings, Celsa A Spina, Ann Wiegand, Alan L Landay, Robert W Coombs, Douglas D Richman, John W Mellors, John M Coffin, Ronald J Bosch, David M Margolis
|title=Depletion of latent HIV-1 infection in vivo: a proof-of-concept study
|journal=Lancet
|month=August 13,
|year=2005
|volume=366
|issue=9485
|pages=549-55
|url=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1894952/
|arxiv=
|bibcode=
|doi=10.1016/S0140-6736(05)67098-5
|pmid=
|accessdate=2012-05-09 }}</ref>

Proof of concept consists of a prototype instrument or device that makes a distant source appear nearer.

===[[Proof of technology]]===

"[T]he objective of a proof of technology is to determine the solution to some technical problem, such as how two systems might be integrated or that a certain throughput can be achieved with a given configuration."<ref name=ProofofConcept>{{ cite web
|title=Proof of concept, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=December 27,
|year=2012
(contracted; show full)|url=http://www.afcee.af.mil/shared/media/document/AFD-071003-081.pdf#page=108
|arxiv=
|bibcode=
|doi=
|pmid=
|accessdate=2012-02-15 }}</ref>


==See also==
{{div col|colwidth=12em}}
* [[w:List of telescope parts and construction|List of telescope parts]]
* [[Radiation]]	
* [[Radiation astronomy]]
* [[Radiation detectors]]
* [[Radiation satellites]]
{{Div col end}}

==References==
{{reflist|2}}

==External links==
* [http://www.ajol.info/ African Journals Online]
* [http://www.bing.com/search?q=&go=&qs=n&sk=&sc=8-15&qb=1&FORM=AXRE Bing Advanced search]
* [http://books.google.com/ Google Books]
* [http://scholar.google.com/advanced_scholar_search?hl=en&lr= Google scholar Advanced Scholar Search]
* [http://www.iau.org/ International Astronomical Union]
* [http://www.jstor.org/ JSTOR]
* [http://www.lycos.com/ Lycos search]
(contracted; show full)[[Category:Original research]]
[[Category:Physics and Astronomy]]
[[Category:Research]]
[[Category:Resources last modified in September 2015]]
[[Category:Technology]]
{{experimental}}{{article}}{{lecture}}{{astronomy}}{{Materials science}}{{technology}}

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