Crescent Nebula



Description

The Crescent Nebula (also known as NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in the constellation Cygnus, about 5000 light-years away. It was discovered by Friedrich Wilhelm Herschel in 1792. 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.

Equipment and processing

Telescope: Meade SN6

Mount: Meade LXD55

Camera: Canon T1i

Filters: Astronomik Ha 12nm, OIII 12nm

Guiding: PHD

Processing: Photoshop, DSS, Fitswork

Capture software: BackYardEOS

Exposures: 35x300 ISO3200 Ha,81x600 ISO3200 OIII

Location: Parsippany,NJ

Comments


Comments powered by Disqus