Difference between revisions 1287129 and 1290700 on enwikiversity

[[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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=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: .]]

From the Wikipedia article [[w:|Refracting telescope]]: "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 
|isbn= 0-900099-15-1
|pages= 233–7
(contracted; show full)ates]  in the [[w:radio frequency|radio frequency]] portion of the [[w:electromagnetic spectrum|electromagnetic spectrum]] ... Radio telescopes are typically large [[w:Parabolic antenna|parabolic]] ("dish") antennas used singly or in an array. Radio [[w:observatory|observatories]] are preferentially located far from major centers of population to avoid [[w:electromagnetic interference|electromagnetic interference]] (EMI) from radio, [[w:TV|TV]], [[w:radar|radar]], and other EMI emitting devices.”
 from the Wikipedia entry about the [[w:Radio telescope|r<ref name=RadioTelescope>{{ cite web
|title=Radio telescope, In: ''Wikipedia''
|publisher=Wikimedia Foundation, Inc
|location=San Francisco, California
|month=29 January
|year=2015
|url=https://en.wikipedia.org/wiki/Radio  _telescope]].⏎
|accessdate=2015-02-03 }}</ref>
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=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.]]
(contracted; show full)#x27;'' or '''alt-azimuth mount''' is a simple two-[[w:coordinate axis|axis]] mount for supporting and rotating an instrument about two mutually [[w:perpendicular|perpendicular]] axes; one vertical and the other horizontal. Rotation about the vertical axis varies the [[w:azimuth|azimuth]] (compass bearing) of the pointing direction of the instrument. Rotation about the horizontal axis varies the [[w:altitude|altitude]] (angle of elevation) of the pointing direction.”
 from the <ref name=AltazimuthMount>{{ cite web
|title=Altazimuth mount, In: ''Wikipedia''
|publisher=Wikipmedia article about the [[w:Foundation, Inc
|location=San Francisco, California
|month=17 January
|year=2014
|url=https://en.wikipedia.org/wiki/Altazimuth  _mount⏎
⏎
|altazimuth mount]].ccessdate=2015-02-03 }}</ref>

“When used as an astronomical [[w:telescope mount|telescope mount]], the biggest advantage of an alt-azimuth mount is the simplicity of its mechanical design. The primary disadvantage is its inability to follow astronomical objects in the [[w:night sky|night sky]] as the [[Earth]] spins on its axis the way that an [[w:equatorial mount|equatorial mount]] can. Equatorial mounts only need to be rotated about a single axis, at a constant rate, to follow the rotation of the night sky ([[w:diurnal motion|diurna(contracted; show full)
| accessdate = 13 March 2011 }}</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.”
 per the Wikipedia article about the [[w:<ref name=Altazimuth mMount|altazimuth mount]]./>
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=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.” from the Wikipedia article about the [[w:<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|telescope mount]].⏎
|accessdate=2015-02-03 }}</ref>
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=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.” per the Wikipedia article on the [[w:<ref name=Telescope mMount|telescope mount]]./>
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=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: .]]
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