Technical card
Crescent and Soap Bubble Nebula HOO
Dates: 12. July - 23. July 22
Locations: Home, Kanton Bern, Switzerland, Gurnigel, Bern
- Camera: ZWO ASI294MM Pro
- Mount: Skywatcher EQ6r Pro
- Telescope: Explore Scientific ED 102 APO
- Others: ZWO EAF, ZWO EFW
Exposure Details: Total integration time 19.15 HRS, 131x300 Ha, 100x300 OIII
Information from the author
The Crescent Nebula (also known as NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in Cygnus's constellation, about 5000 light-years from Earth. It was discovered by William 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.
