NGC 6888 shown here in RGB plus H-Alpha all un binned. Shot from my backyard in Fremont MI, over 5 nights at 2400mm (native focal length of the AT12RC) using the QHY9M Monochrome CCD. Total Exposure time 18.6 hours Thanks for looking and commenting. All the Best & Clear Skies Terry Down Under Observatory Image Information Location: DownUnder Observatory, Fremont MI Date of Shoot July 10th, 11th, 12th, 13th and 17th 2012 Exposure: RGB 22x10 mins, 4x15 mins each un binned H-Alpha 8x30 mins, 1x40 mins un binned Camera: QHY9M monochrome CCD, cooled to -30C www.astrofactors.com StarlightXpress Color Filter Wheel Scope: Astronomy Technologies Astro-Tech 12" f/8 Ritchey-Chrétien astrograph Autoguided using StarlightXpress Lodestar autoguider, StarlightXpress Ultra Slim Off Axis guider Paramount GT-1100S German Equatorial Mount (with MKS 4000) Image Aquisition software Maxim DL5 Stacking software CCDStack Post Processed with Photoshop CS5 The Crescent Nebula, a very popular target for astrophotography is also known as NGC 6888 and Caldwell 27 and is often referred to as "The Brain" Nebula unofficially because of it's likeness to the human brain, seen here in H-Alpha it is surrounded by the very dusty region of hydrogen filiments. In the constellation Cygnus about 5000 light years away it is classified as an emission nebula.