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Old 09-09-2016, 05:08 AM
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ags_ (Phil)
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Join Date: Sep 2007
Location: Rubyvale Qld
Posts: 417
Quote:
Originally Posted by Stonius View Post
I don't know - are those dark bands in the northern hemisphere cloud detail?

Markus
Hi Markus, yes those bands are real but as for detail more like a hint of shading is all than can be expected. Neptune is 2.4" dia and under excellent conditions my scope is capable of 0.085"/pixel or 12 pixels per arc/sec so a maximum of 30 pixels across Neptune. To see any individual high contrast feature in very steady seeing at least 4/5 pixels are usually needed so on Neptune only features 20% of it's dia can be reliably seen. That's why at least 2 images with a rotational gap during a session are required to prove any new feature is real and over several different days.

Regards, Phil
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