Sh2-155 or Caldwell 9, also called the Cave Nebula. Located in the constellation Cepheus, it is a complex nebula containing emision, reflection and dark nebulosity. Image shown at 50% of original size
Location: Pozuelo de Alarcon, 10 km away from Madrid (Spain). Zenith sky brightness: 18,0 to 18,4 magnitudes/square arcsec
Scope: Vixen VC200L at 1800 mm focal length.
Mount: ASA DDM85, unguided tracking
Camera: SBIG STL11000. Filters: Luminance, Red, Green, Blue and Hydrogen alpha. CLS-CCD light pollution filter.
Exposure: 1905 minutes total exposure in 15 minutes sub-exposures (510 min Luminance, 270 min Red, 345 min Green, 330 min Blue, 450 min Hydrogen alpha)