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Old 02-02-2014, 11:00 AM
Peter Ward's Avatar
Peter Ward
Galaxy hitchhiking guide

Peter Ward is offline
 
Join Date: Dec 2007
Location: The Shire
Posts: 8,483
Just to give these numbers a real-world perspective, while my PME has a PE of around +/- 2.5 arc sec, when guiding at 1 second intervals, I typically see RMS pixel errors of 0.18 on Dec and 0.2 in RA

That's about 0.3 arc sec for the focal length I'm currently using. This is well below the 2-3 arc sec seeing I get most nights....any is pretty typical for most sea-level locations in Oz.

Would an RA drive pottering along with a 0.2 arc sec error make a difference?

I seriously doubt it, as (A) you haven't solved any Dec dift, and (B) the geometric arc your RA axis is drawing in the sky is unlikely to be perfectly following the path refracted starlight is taking.

Hope that helps.
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