Sh2-155 (The Cave Nebula)

Sh2-155, Also known as the Cave Nebula and 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.The nebula gets its name Cave Nebula from the dark lane abutting the brightest curve of emission nebulosity which gives the appearance of a deep cave when seen through a telescope visually.

I hope you enjoy.  Randal Healey