M20: the Trifid nebula in Sagittarius
The red glow of tis nebula is a diffuse HII region, some of which is blocked by dark interstellar dust clouds. The blue haze around a star is a a reflection nebula: starlight reflected by tiny ice crystals.
Images taken: Sept. 28-29-30, 2008, Kelsey Williams, Stephanie Jabaley, Erin Singleton, Emily Hightower, Kyle Sjostrom, Sarah Gardner.
Telescope: Meade 12 in at f/5.7 (f=68 in).
Camera: SBIG ST-10 CCD camera
Image scale: 1 as/pixel.
Exposures: 3 x 20 min each in red, green, blue: a total of 3 hours.
Image processing: CCDoops + CCDSoft + Photoshop CS.