Chris, Another highly detailed photo but do you really think 10x better than your previous photos with your "old" camera. Definitely 100x better than a Brownie! I wonder to gravitational lensing--when there is a galaxy within the obvious confines of the nearer galaxy, is it _always_ magnified by the gravitational lens? Would a camera still pick all of them up if they weren't magnified by the closer galaxy? Jimmy, As for the inclination of M101 it's actually 17o, and yes, all spiral galaxies are round. There is a set formula to determine the inclination based on the length and width + a few degrees for what radio telescopes pick up beyond that. It's a bit counter-intuitive in that 0 degrees is perfectly face on and 90 degrees is an edge on. The Andromeda galaxy for example is inclined 77+degrees. Does anyone knows where to find a list of galaxy inclinations, even a small list like for the M's would be great for a comparison. Chris, ...The brightest knot in the arms to the upper right of the nuclear region is NGC5462, an complex blue stellar association with a rim of red hydrogen around its energetic core. When we add the hydrogen data to this image, the galaxy dynamics that will become visible here will be simply out of this world.... Actually NGC 5462 is to the left of the nuclear region at about 9:30 with an even brighter NGC 5461 just below it closer to the nucleus. Jenn. ----- Original Message ----- From: "Jimmy Ray" <jimmy_ray@xxxxxxx> To: <az-observing@xxxxxxxxxxxxx> Sent: Thursday, May 24, 2007 7:49 PM Subject: [AZ-Observing] Re: M101 for the month of May Hi Chris, A great shot! I have it up as my desktop picture so I can admire it for awhile. Now for the questions borne of Novice ignorance and curiousity. On your website there are a couple of statements that I'm pondering over: "its inclination is less than 1 degree and is face on to our line of sight." How is this actually calculated and/or figured out? Do all spiral galaxies have a certain degree of "roundness" so any amount of "obliqueness" can be corrolated into degrees of "tilt" or other? "Hordes of faint background galaxies dot this image, most being a leaden yellow color, dimmed from their great distance through intergalactic dust." Is this dust causing the "yellowing" galactic or interstellar dust collecting around the galaxy itself in the plane of or within the gravitational field of that galaxy? Or an unrelated dark nebula somewhere between here and there? And / or is this caused because of the general "dustiness" of the Universe? Jimmy Ray Subject: [AZ-Observing] M101 for the month of May HI all, It took all month to image this one, due to clouds, wind, and giving it lots of exposure time. Anyway, I think youll like the lastest image of the Pinwheel galaxy with our newer ST10xme camera. It does 10x better job on galaxies than the older ST8i with the same setup and exposures! http://www.schursastrophotography.com/ccdimagepages/m101-3.html Comments? Chris Take Care, Chris Astro: http://www.schursastrophotography.com Robotics: http://www.schursastrophotography.com/roboticsmain.html -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.