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Quick question about telescope classification

  1. Mar 26, 2015 #1
    I am slightly confused about what the term 'astronomical telescope' covers. My text book seems to be implying that astronomical telescopes are refracting telescopes with an objective and eyepiece lens, and reflecting telescopes are separate to astronomical telescopes. On the other hand I have read some sources that seem to say that both reflecting and refracting telescopes can be astronomical telescopes because they are used to view planets/stars/moons and the opposite is a terrestrial telescope used for observing things on Earth. Could someone clear up this discrepancy?

    Thank you in advance! :)
  2. jcsd
  3. Mar 26, 2015 #2


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    "Astronomical telescope" usually means any telescope that is used (or designed to be used) for astronomy, regardless of optical design.
  4. Mar 26, 2015 #3

    Doug Huffman

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    As I recall from my youth, when I built an 6" and an 8", astronomical telescopes are not intended to erect the image but require a separate accessory lens to do so.
  5. Mar 26, 2015 #4


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    no that is totally incorrect
    astronomical telescopes are either, infact all of the major astronomical scopes are reflectors .... even the Hubble Space Telescope

    There are 2 exceptions, the Yerkes Observatory in WI, USA is a 40 inch refractor and the largest in the world .... was built in the 1890's
    And the Lick Observatory on Mt Hamilton, CA, USA, which sports a 36" refractor, also built in the last 1880's

    For amateur astronomy, I have owned both types, currently own 8" and 9.25" reflectors

    terrestrial telescopes ( including binoculars) are all refractors .... completely the opposite to your opening statement

    The only difference between a terrestrial refractor and an astronomical refractor is that the terrestrial one has an extra lens built into it to invert the image so that it is upright for viewing. Some astronomical refractors may come with or have an accessory lens that can invert the image for terrestrial use

    Last edited: Mar 26, 2015
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