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Old 07-10-2019, 08:51 PM
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gregbradley
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Join Date: Feb 2006
Location: Sydney
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Quote:
Originally Posted by Slawomir View Post
Thank you for confirming that Greg.

I did a quick calculation for the Helix, and it would take about 40 years to have the nebula expand by one pixel when imaging at 1 arcsec per pixel. It would be even less movement for the most of the objects located further away. So we should be able to integrate data collected even a few decades apart without any noticeable effect on the sharpness of the image, maybe with an exception for the few really fast moving stars.
The distances are so vast that even if the relative speeds are large the angular shift would be tiny.

Quote:
Originally Posted by Paul Haese View Post
It's a nice composition Greg with lovely colour. Little refractor like stars too.
Cheers Paul. When the tilt is dialled in the stars do become quite pinpoint which is great for an astrograph.

Greg.
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