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For those of us who are not extremists, I think a nice mix of showpieces, faint fuzzies, "the hunt", the familiar, and the occasional planet or Moon provide a good variety of challenge and esthetics. Even including failures in the program helps sharpen the edges of success: not seeing something at all is hardly esthetic, but it teaches you the difference between observation and imagination; I think some do not work very hard at this.

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The folks w/12"+ stay busy teasing out faint galaxy arms

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If M51 counts for faint galaxy arms then I've managed to make them out using a 60/1000mm refractor with a Meade 14mm UWA eyepiece at 71x. From my notes:

July 12, 2009 NELM: 5.25mag skies (direct vision)
Seeing: 8/10 Transparency: 9/10

M51 & NGC 5195: 14mm UWA w/averted vision brought out the spiral structure of M51 and the bright core of NGC 5195. Amazing detail for such a small instrument!

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M51 to me in a small scope has never ever really shown much in the way of clear spiral arm structure. Oh, in a 60mm aperture, you can easily tell from the brightness profile that it *is* spiral, but the actual spiral structure doesn't really start to show up much until you get to around five or six inches of aperture (and even then, the spiral form is vague at best). Below five or six inches of aperture, you get a sort of "fuzzy ring" like formation around the brighter core. When I first saw M51 as a kid from a dark sky in my 2.4 inch f/11.7 refractor, all I could see was a fuzzy round patch of light with a smaller brighter distinct core region and the companion galaxy NGC 5195 sitting next to it. In a 90mm Mak-Cassegrain, with averted vision, I could just begin to see a little hint of a vague ring-like formation around the core, and by 4 inches, it looked like a mottled ring with maybe just a hint of structure to it. By eight inches, the spiral structure was fairly easy to see from a dark sky site, although tracing some of the arms was a little difficult at times. At 10 inches, some detail in the arms becomes visible, along with a little of the connection between the main galaxy and its companion. Most of us are very familiar with the nice pictures of M51 and know it is a spiral galaxy with some of the most distinct spiral structure of any galaxy available to the amateur. However, in a small aperture, one has to be a little careful to draw the line between what is actually seen and what might be due to a little "averted imagination". Clear skies to you.

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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org

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Hi David, I understand about the averted imagination; however, this spiral structure was indeed there as clearly evident with my larger 120mm refractor. NGC 891 is really not much of a challenge to me either in a 60mm (I found it under the 1st quarter Moon) as that was the scope I first found it in. Plus, I even detected a dark dust band running through it even before I knew that this particular galaxy had that feature. Same thing with NGC 604, not a problem. NGC 3226 and 3227 are quite discernable as well. All of these galaxies were first detected with a 60mm telescope. The 13th mag star east of M57 is also pretty easy for me to see with slight averted vision. My current location allows me access to dark skies so I'm sure this helps.

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I have *detected* NGC 891 in a 60mm aperture, but it was so marginal that if I hadn't first found it in my 10 inch, I could easily have gone right past it without noting it at all (this was under a dark sky with *no* moon). NGC 891's dust lane in anything much smaller than a six or eight inch is probably wishful thinking (unless an image intensifier is used). Under a first quarter moon, the galaxy itself is nearly invisible even in a six inch. On M51 in my 4 inch refractor stopped down to 60mm at 75x, I can see a little vague large-scale mottling in the very faint outer haze, but again, no clear spiral arms or arm structure. In an NP101 at the Nebraska Star Party a number of years ago, I could get a little of the spiral structure, but the outer haze still was more a patchy ring-like formation than something with clearly-visible and distinct spiral arms. NGC 604 is not a problem in a small aperture, as it is fairly concentrated (a friend of mine's 12x50 binoculars will show it). However, a claim of clear spiral arm structure in M51 or the dust lane in NGC 891 being visible using only a 60mm aperture may (at least for me) be just a little bit hard to believe. Clear skies to you.

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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org


Edited by David Knisely (07/17/09 02:31 AM)

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