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Old 20-01-2021, 09:08 PM
sneaks (Paul)
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Star Adventurer Pro 2i drifting... help please!

I have what I think is a good polar alignment, and decided to track a star in Orion to test how long it would remain centered while on max zoom.

With the mount completely off, the star drifts in my image from bottom to top. Turning sidereal tracking on almost perfectly nullifies this drift, which is great.

However, the star slowly but surely also drifts from right to left in the image. And I don't know what the cause of this is. It is drifting slower than sidereal rate for sure, but has definitely moved after 60 seconds or so, enough to make a long exposure blurred.

Thankful for any advice you can give!
Paul.
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Old 20-01-2021, 09:47 PM
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Rerouter (Ryan)
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as its a drift mostly in declination, I can only imagine either your mount was not level before you started polar alignment, or something was wrong about your alignment process
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Old 20-01-2021, 10:20 PM
sneaks (Paul)
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I think you're right, because when I went back to check the polar alignment it was off.... it seems rather easy to ruin the alignment when you release the clutch to line up on your target. Gonna have to find a solution to that.
Thankyou!
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Old 21-01-2021, 02:46 AM
astro744
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Polar alignment is definitely out. Search the web for “Star drift method of polar alignment in Southern Hemisphere”.

I found this but there are many other sites:

https://www.assa.org.au/resources/eq...lar-alignment/

You need to learn the cardinal directions as viewed through the eyepiece, i.e. N, S, E, W. The image may be reversed depending on the total number of reflections, I.e. odd = reversed, even = not reversed although either could be rotated depending on how you orient yourself with the telescope. Learning the cardinal directions avoids ambiguous descriptions like up/down, left/right because these depend on which side of the meridian the object is, which way you are facing and the telescope type (reversed view or not) and if describing to someone else then that person can not determine if left is north, south, east or west.

Best way is to nudge the tube as you look through and see which way the sky moves. e.g. if you nudge North then anything that was on the northern edge in the eyepiece will move toward the centre. Once you have identified the cardinal directions you can then follow the instructions for star drift alignment.
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