Cave Nebula Sh2-155 or Caldwell 9
Date: 12/24/2014
Description: Sh2-155 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 Cave Nebula 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.. [Ref: WikiPedia]
Sky Conditions: Clear sky, medium - urban light pollution (no moon), FWHM: 2.5 - 3.0 arc sec/pixel
Imaging: Exposure: 4x60 min (LRGB, 9 x 400sec/ea.) at 2x2 bin using RGB filter
Guiding: 6 sec at 2x2 bin using NOAG
Equipment:
SBIG STF8300M CCD (RGB, Ha filters)
AT12RC at F8
Starlight Focuser NOAG w/SBIG ST402 guide camera AP1200 Mount
SW: Maxim DL V6, FocusMax, AP ASCOM V2, SkyX, PixIsight - calibration with darks, flats, bias.