If you check, you'll find that the Astronomical League includes a Caldwell Club.

not sure if its appropriate but i figured i'd plug kents site here, he's got alot of great pictures.

Alan? My oops. It is polycyclic and the article has been changed to reflect that. (this is what happens to your brain after you get old and listened to a whole lot of pink floyd and did things you advise others not to do when you were young but still did 'em and probably still would if given half a chance.) Whenever I feature an astrophoto, I like to do more than just look at a pretty picture, so here's the scoop on what we learned last time:

"What this comes down to is carbon nanoparticles are out there in the interstellar medium. Polycyclic aromatic hydrocarbons – or PAHs – are molecules constructed of benzene rings that look like segments of single layers of graphite. If you were here on Earth? You'd find them everywhere… coming out of your car's exhaust, stuck to the top of your grill, coating the inside of your fireplace. Apparently we're picking up the signature of PAHs in Unidentified Infra-Red emission bands, Diffuse Interstellar Bands and a UV extinction bump in NGC 7023 – but what the heck is it doing there?

According to research, it's entirely possible these PAHs may have formed in the dust when the grains collided and fractured – releasing free PAHs. They could have grown between smaller unsaturated hydrocarbon molecules and radicals in the remnants of carbon rich stars. Science just doesn't really know. But one thing they do know… Once a PAH is there, it is extremely stable and extremely efficient at rapidly re-emitting the absorbed energy at infra-red wavelengths."

Now! Jeff? Heheheheeee…. I can't go knockin' Sir Patrick Moore. He created an alternative observing list with the Caldwells and if I could get away with publishing a book of my own observing favorites, I probably would. I can see it now… "The Plotner Project"… 288 of your favorite deep sky gems… all listed by RA except for… oops! Anyhow, no offense. You've made a very valid point and it should be noted to readers that the Caldwell objects are an observing list and not a genuine catalog of studies.

For Autumn and Richard…

Remember when it comes to seeing the North American Nebula, it's BIG. If you're observing from a dark sky site dark enough to pick out the Andromeda Galaxy easily, chances are you can see NGC 7000, too. The whole complex is about the size of a vanilla wafer held at arm's length and bigger than most binocular fields! The problem is, once you apply optics to it, the optics dim the already low surface brightness and magnfication means you're looking a just a few trees and not the whole forest. Here's a map to give you an idea of what you're up against.

Now, the second thing to remember is that it is dim. Kick back in a lawn chair and just start looking in the area but not directly at it. (yep. averted vision.) You'll pick out that hazy cloud, but the problem is your eye wants to go directly to it to try and identify the shape. Look for a silver-ness… A patch that definitely glows and stands out from the general starfields.

Image courtesy of the Hawaiian Astronomical Society

Then what happens? Ooops. There it goes. You've lost it because you looked directly at it. This is why we can only see the NGC 7000 "North American" shape when it's photographed. The whole thing is too dim to be focused directly on by the human eye and not all wavelengths of light can be caught by the human eye. Special filters in telescopes go a long way to seeing details in small areas, though!

Bunnyman? Giggle… I'm honored!

http://calgary.rasc.ca/images/MoonAndNGC7000.gif

I must have missed that, what do they mean?
Oh and should that be Polycyclic?