http://www.galaxyphoto.de/m20m21_I.htm
M20 is a combination of reflection - emission - and dark nebula, located in Sagittarius. The image also shows M21, an open cluster of stars and a minor planet. It is Auravictrix, which left a trail below the red part of M20.
Telescope: 4,5" - Newton, f = 440mm + Vixen R200SS, f = 800mm
Camera: SBIG ST2000XM
Exposures: L:R:G:B 30x3min + 12x5min: ( 8x3min + 2x5min each )
Location: 30km nw from Munich / Germany
Date: 07/02/10 + 07/04/05