Crescent Nebula
From Wikipedia, the free encyclopedia
| Crescent Nebula | |
 A Hubble Space Telescope (HST) image of NGC 6888. Credit: HST/NASA/ESA. |
|
| Observation data: J2000.0 epoch | |
|---|---|
| Type | Emission |
| Right ascension | 20h 12m 7s[1] |
| Declination | +38° 21.3′[1] |
| Constellation | Cygnus |
| Physical characteristics | |
| Radius | - |
| Absolute magnitude (V) | - |
| Notable features | - |
| Other designations | NGC 6888[1], Sharpless 105 |
| See also: Diffuse nebula, Lists of nebulae | |
The Crescent Nebula (NGC 6888 or Caldwell 27) is an emission nebula in the Cygnus constellation, 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 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.
[edit] External links
[edit] References
 |
This astronomy related article is a stub. You can help Wikipedia by expanding it. |
