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Declination and Right Ascension


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Dec is straightforward.

Set:

-the Declination dial set at 90deg

-RA at 2:31.8 or 2.53hr or 37.95deg

Then you align the Telescope's Declination to the North Star (Polaris) then lock it in and do not change it. Right?

RA is harder to understand. First the mount is on an Arc. Second the base swivels. My telescope does not have a scale for the base swiveling.

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I am no expert either but think you might be confusing altitude (alt) and azimuth (az) with RA and Dec. You set up your (presumably equatorial) mount using an appropriate azimuth - left and right motion and altitude - up and down motion. once these are set you only need to tweak them as below each time you observe. your azimuth should point at Polaris and your altitude at your own latitude (eg Manchester is about 53 degrees). This is enough for rough visual alignment but if you are tracking then you need to follow the procedure for drift alignment or polar alignment more thoroughly.

With this done you then use your mount to follow RA - left to right motion on a curve via the mount and declination - up and down movement via the mount.

hope this helps a little.

Altazimuth mount - Wikipedia, the free encyclopedia

Equatorial mount - Wikipedia, the free encyclopedia

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It would help to know what sort of scope and Mount you have, and whether it is motorised, as set up procedures can vary.

i.e. Is it manual, or motorised?

Is it Alt/Az or equatorial?

If it's an ETX I can explain that procedure.

If it's Equatorial, then you need to point the polar axis at Polaris etc etc

If it equatorial motorised you need to set date and time and location etc etc

Let us know what you have and we can supply a better response.

Carole

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Sky-Watcher 130mm Eq2 Reflector Telescope

•130mm (5.1 inch) diameter primary mirror made from grade-A glass and multi-coated for optimal reflection

•900mm focal length, f/6.9

•20.4 sq. in. light grasp

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•High-quality super Plossl fully-coated 25mm and 12mm 1.25” eyepieces provide clear, sharp images at magnification of 36x and 75x with a 52° apparent field-of-view and great eye relief

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•Red-dot finderscope with variable brightness makes locating night-sky objects easy

•Stable 1.25" rack-and-pinion focuser

•EQ-2 equatorial mount provides proper stability with dual slow-motion controls, 360° azimuth adjustment

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You clearly have an EQ mount (the EQ2) but to be honest, the RA and DEC setting circles fitted to the smaller EQ mounts are not a great deal of use - they are too small and imprecisely made to be accurate.

Provided your RA axis is pointing roughly north and you have set the latitude scale to suit your observing location, the mount will track accurately enough for visual observing.

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Even though using the primative Equitorial Base how do I use the RA dial. In adjusting to the North Star do you also set the RA of Polaris (about2:31.8) to get a truly accurate setting.

Rotate the base to view a different star by changing the Dec dial 0-90 to set the star's DEC. The Swivel of the base will mess up any RA setting from the North Star Set the RA dial to the RA of the star and swivel the base till the star comes into view.

Is it truly that easy?

Edited by Philosophaie
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