Optics/mount: 180 Epsilon f2,8 Takahashi Mount CI700 Clestron
Camera/filters:QHY 12
exposure: 35×900 sec
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 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.