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. Visually it is a difficult object, but with adequate exposure, makes a striking image. The nebula gets its name from the dark lane abutting the brightest curve of emission nebulosity which gives the appearance of a deep cave. This image was taken over 6 nights and totals 13 hours of exposure. It contains luminance and RGB data, as well as 2 hours of h-alpha images. The h-alpha was blended into the RGB at different levels to provide detail. This image was taken beginning on September 28, 2010, and the last images were taken October 7, 2010. High winds on some of the nights made image acquisition a challenge. Click on the image to see it at a larger scale.