These two objects are neat to image and it's interesting that NGC6946, The Fireworks Galaxy, is 22.5 million light years from us while the open cluster NGC6939, is only 5,000 light years away. This image is from the Edge8" with Hyperstar and is about 2 hours total exposure at F2 with the Atik 428EX color camera.
Frank N
Stellarvue 80mm APO, Skyguider Pro, Celestron AVX
"I'm a seeker too. But my dreams aren't like yours. I can't help thinking that somewhere in the universe there has to be something better than man. Has to be"
Great composition, Frank. What an interesting field of view. Nice detail in the galaxy, too. I think I can just make out some red Ha regions in the spiral arms.
It's a challenge to try to grapple with the scales involved, having an enormous galaxy at a great distance at about the same apparent size and brightness as a "close" open cluster. Scaling things down to human proportions: if the cluster was in my kitchen (40 ft away), the angular size of 11 arc-minutes would make it about 1.5 inches in diameter. At that scale, and the same angular size, the galaxy would be 34 miles away and 576 ft in diameter (the superman building in Providence is 428 ft high).
Andy we have a boxed presentation "The Scale of the Universe" which is pretty good, especially when it's personalized as I do when I have done it in the past. If you (or anyone) wants to use it for a school or scout etc. presentation I have it.
That was a cool explanation on the scale aspect of these objects. Yes, it is very daunting to try to understand the relative scale of objects in the universe and it's one of the things I wrestle with all the time. I try to explain to non-astro folks about the distances and sizes and typically, understandably, their eyes begin to glaze over. Thanks for the comments
Frank N
Stellarvue 80mm APO, Skyguider Pro, Celestron AVX
"I'm a seeker too. But my dreams aren't like yours. I can't help thinking that somewhere in the universe there has to be something better than man. Has to be"
Thanks, Bruce
I bet you got some time in under the stars last week too. It was a nice break in the otherwise poor observing period this season.
Frank N
Stellarvue 80mm APO, Skyguider Pro, Celestron AVX
"I'm a seeker too. But my dreams aren't like yours. I can't help thinking that somewhere in the universe there has to be something better than man. Has to be"
I'm green with envy Frank. We've had absolutely lovely skies this past month but I'm under construction and pretty much limited to sitting out on my deck at night and utilizing the 'ol Mark I eye ball.
Thanks for the comments 