This is an image of SH2-155, the Cave Nebula. It is a dim and very diffuse nebula within a larger nebula complex containing emission, reflection, and dark nebulosity. It is about 2400 light years away in the constellation Cepheus. 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.
September 20, 2011
Location: Rancho Hidalgo, NM
Telescope: TEC-140 (F7)
Camera: SBIG ST-8300M
Mount: AP900 GTO
Ha: 8x15 minutes (unbinned)
Luminance: 12x10 minutes (unbinned)
Red: 6x10 minutes (binned 2x2)
Green: 6x10 minutes (binned 2x2)
Blue: 6x10 minutes (binned 2x2)