S 155
| Emission nebula | |
|---|---|
 S 155 | |
| Observation data: J2000.0 epoch | |
| Right ascension | 22h 57m 17.14s |
| Declination | +62° 28′ 33.4" |
| Distance | 2400 ly |
| Apparent magnitude (V) | 7.7 |
| Apparent dimensions (V) | 50.0'x30.0' |
| Constellation | Cepheus |
| Physical characteristics | |
| Radius | 35 ly |
| Absolute magnitude (V) | 16 |
| Designations | Sh2-155, Caldwell 9 |
S 155, also known as the Cave Nebula, Sh2-155 or Caldwell 9, is a dim and very diffuse bright nebula within a larger nebula complex containing emission, reflection, and dark nebulosity. It is located in the constellation Cepheus.
Visually it is a difficult object, but with adequate exposure, makes a striking image. The nebula gets its name Cave Nebula from the dark lane at the eastern side abutting the brightest curve of emission nebulosity which gives the appearance of a deep cave when seen through a telescope visually.
References
Patrick Moore (1990). The Amateur Astronomer (11th ed), W.W. Norton & Company, ISBN 0-393-02864-X
External links
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Wikimedia Commons has media related to S 155. |
- S 155 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
- The Scale of the Universe (Astronomy Picture of the Day 2012 March 12)
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This article is issued from Wikipedia - version of the 6/28/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.