Quote:
Originally Posted by Allan
The Cone nebula is a good example of a target that is tough even in the 32”. I never saw it in my 12”. Don has good eyes and some higher altitude sites, so he might have seen it in his 12.5”. But he would be one of the few humans to do it in that size scope.
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Allan,
While the Cone Nebula is a very challenging target in most amateur telescopes, it should be fairly routine in a 32" scope under Bortle 1 skies, particularly so, if you use a H-Beta filter. I've observed it at Ozsky, in all of the scopes we take to Ozsky from 14" to 30" at different times. It certainly isn't easy. One night we spent a good bit of time on it in my 18" scope. 3 of us could see it fairly comfortably with a UHC filter (Andrew Murrell, myself and Lance Humphries), yet another 1/2 a dozen people, including some experienced observers like Alan Dyer, could not see it. Hartung regularly observed it in his 12" scope, with a H-Beta filter. I would say it's definitely tougher than the Horsehead, but achievable in 12" scopes by skilled observers under ideal conditions. The planetary nebula that Andrew Murrell discovered (Murrell 1) is certainly a lot tougher and James Peirce, Andrew Murrell and I have observed that in James's 16" scope from Coonabarabran. The Cone Nebula certainly isn't a beginners target in a 12" scope, but I know at least 6 people personally who would be capable of it. I can guarantee you the worldwide list extends far beyond Don.
Cheers,
John B