Location / Date

Zellerndorf, 13., 28. und 30. June 2011

Telescope / Mount / Guiding

10" f4,7 Skywatcher Newtonian, Baader MPCC, Skywatcher NEQ6, Lacerta OAG + Mgen

Camera / Exposure

Canon EOS 1000Da, 42 x 15min ISO 200 (total 10h 30min)

Processing

Theli, Photoshop

Notes

The Crescent Nebula is an emission nebula in the constellation Cygnus, about 5000 light years away.
It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago. The result of the collision is a shell and two shock waves, one moving outward and one moving inward. The inward moving shock wave heats the stellar wind to X-ray-emitting temperatures.