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Stargazing Telescope mount questions.

  1. Jun 26, 2005 #1


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    A few months back my brother dug this telescope of his garage and brought over to mine. I have had it out and was able to get a good look at the last quarter of the last moon, and a good look a Jupiter, with 2 moons visible. Somewhat to my surprise I was even able to resolve a couple of bands (pretty faint) on Jupiter.

    Here is the telescope


    now for my question, I am having some trouble setting up the mount so the co-ordinate system is correct. Could someone give me some guidance.

    First of all have I got the telescope in the correct orientation?


    I am having trouble locating the fiducial mark on ring A, I may have to make one, but that fiducial will be pointing North.

    I have ring B set to my local latitude (~45) and believe that it should remain fixed there, is that correct?

    Rings C & D should be Right Ascension and Declination but I am not sure how to align them.

    Any pointers or direction to a web page with a complete description of this sort of mount would be appreciated.
  2. jcsd
  3. Jun 26, 2005 #2


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    This is a typical commercial German equatorial mount. As for orientation, you will have to align the mount every time you take the scope outside. Luckily, for visual observations, this is pretty fast and easy.

    The markings on ring A are of no consequence. Since the mount is on a portable tripod, it will have to be re-aligned every time you set it up. Just ignore those marks.

    If the place where you set up the tripod is absolutely level, and you set up the same way every time, it's a fair approximation. The scale is only a rough guide, though.

    Ring C is the right ascension circle. It is numbered 1 through 24 for the 24 hours in the day. The shaft running through this ring is called the right ascension axis, and it needs to be aligned so that it is parallel to the Earth's axis of rotation. Making this axis point at Polaris is a good enough approximation for visual observations. You can turn the right ascension worm gear ever so slightly as objects drift out of your view, so you won't have to constantly fiddle with re-acquiring objects. If you want to align a bit more carefully, here is a guide:


    You can find others by Googling on "German equatorial" and "Polar alignment" - be sure to use the quotation marks for best results.

    If I may give you some advice: Your most useful accessories will be an atlas (Peterson's Field Guide to the Stars and Planets is a great starter) and a low-power or zero-power viewfinder. Learn to star-hop from bright easily-found objects to the fainter ones, and forget about those setting circles. They are far too small and imprecise to be useful. An old pair of 7x50 binoculars can often help you find interesting things to look at with the 'scope, too.

    A tip about mechanics: If the 'scope is properly balanced, you can often clutch a German equatorial mount "just enough" to allow you to slew to an object by hand, then use the RA knob to keep the object in view while observing. You'll have to get a feel for it, but it makes observing effortless once you get it right.

    Please feel free to ask for clarification if I haven't answered your questions.
    Last edited: Jun 26, 2005
  4. Jun 26, 2005 #3


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    Thanks alot, you have given me enough to get on the right track.
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