The Crescent Nebula is an emission nebula in the constellation Cygnus, about 5000 light-years away from Earth.
It is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star.

Technical info:
TS 80mm f6 APO triplet refractor -
Canon 40D + IDAS LPS2 (light pollution) filter - exposure 35 x 300sec ~2 1/2 hours
Canon 40D mono (bayer matrix removed) + 12nm Ha filter.
Exposure: 34 x 600sec ~5 1/2 hours.
Total integration: 8 hours

Reprocessed with Astro Pixel Processor