S 155

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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