Crescent Nebula
Sign in to saveAlso known as New General Catalogue 6888, C 27
supernova remnant in the constellation Cygnus
Key facts
- Right ascension
- 20 12 7
- Declination
- +38 ° 21.3 ′
- Distance
- 5,000 ly
- Apparent magnitude v
- +7.4
- Apparent dimensions v
- 18′ × 12′
- Constellation
- Cygnus
- Designations
- NGC 6888, Sharpless 105, Caldwell 27
via Wikipedia infobox
Wikidata facts
- Instance of
- H II region
- Constellation
- Cygnus
- Image
- CrescentBicolorHunterWilson.jpg
Show 11 more facts
- time of discovery or invention
- 1792-09-15
- spectral class
- WN6b(h)
- Commons category
- Crescent Nebula
- Commons gallery
- NGC 6888
- discoverer or inventor
- William Herschel
- catalog code
- Caldwell 27
- apparent magnitude
- 7.44
- right ascension
- 303.0292
- epoch
- J2000.0
- declination
- 38.3550
- has cause
- V1770 Cygni
Sources (2)
via Wikidata · CC0
~2 min read
Encyclopedic overview
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 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 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.
Visibility
Excerpted from Wikipedia’s “Crescent Nebula” article, available under the CC BY-SA 4.0 licence.