I've observed the Cas A SNR several times under decent to excellent sky conditions and had my best view to date at last years Oregon Star Party. The first time I saw Cas A I was surprised how easy the brightest segment was to see in my 28 inch - heck, I was amazed that Bill Gates had seen it through his 9.25 inch SCT - and after repeated observations I've now started to think that the other half of the loop should be visible on a superb night at altitude. Maybe that's wishful thinking on my part, but I wonder if anyone here has seen both loops? I've attached my current sketch to show what I've seen so far.
Cas A for Hawaii presentation_adjusted_inverted.jpgCas A for Hawaii presentation_adjusted.jpg