NGC 6888 Crescent Nebula
Magnitude: 7.4
Distance: Aprox: 5,000 light-years
Constellation: Cygnus
An emission nebula discovered by Friedrich Wilhelm Herschel in 1792. It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 colliding with and energizing the slower moving wind ejected by the star when it became a red giant. 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.
It is a rather faint object located about 2 degrees SW of Sadr. For most telescopes it requires a UHC or OIII filter to see.
Taken 2/17/18 in Chiefland Florida by Russell Kille on a CPC 1100 with Hyperstar @ F2 and ZWO ASI294MC Pro camera
