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Crescent Nebula
The Crescent Nebula, also cataloged as NGC 6888 and as Caldwell 27,  is an expanding shell of hydrogen gas measuring 16 x 25 light years across in the constellation Cygnus.  The name "crescent" is evoked by its ethereal glow in the shape of a young moon, when viewed through large backyard telescopes.  The red glowing hydrogen gas is illuminated by the central brilliant Wolf-Rayet star.  Wolf-Rayet stars shed huge quantities of material, which can collide with hydrogen gases that previously constituted the star's outer atmosphere. A similar process creates the spectacular Bubble Nebula, which I have imaged as both a wide-angle view from my backyard and in closer detail at New Mexico Skies observatory. 

Two hours of imaging with an ST10-XME camera through a Celestron C8 and a 0.67x reducer was utilized. The luminance of 13x5-minute exposures in H-alpha were blended with 3x5 minute exposures through a red filter to create the red channel.  Three green and five blue 5 minute exposures completed the set. 
Music - Aqualung, by Jethro Tull