Sh2-155

The Cave Nebula, Sh2-155 or Caldwell 9, is a bright class E nebula within a long nebulous complex, containing emission, reflection and dark cloudiness. It is located in the constellation Cepheus.

Visually it is a difficult object, but with adequate exposure, it makes a striking image. The nebula owes its name to the dark portion located on the eastern side that borders the glowing curve of nebular emission giving the appearance of a deep cave when viewed through a telescope. Bibliography

Moore, Patrick (1990). The Amateur Astronomer. ISBN 0-393-02864-X. 

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