Sh2-155. Cave Nebula.

Note
Short exposures to work with, so hard processed.


About
IThe 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.

Processing
CCD Stack and CS5

Exposure
Ha: 5x10 min, Lum: 35 min.
RGB: 20min, Bin2.

Calibration
Darks, bias and flats.

Filters
Baader LRGB. Baader Ha 7nm.

Cooling temp
-20´ C

Mean FWHM
3.00"

Date
September 24th 2011

Location
Krigslida, Stockholm, Sweden.
N59 06 52.4    E 18 03 54.5

Image aqusition
MaximDL Pro

Scope control
Sky X Pro Native drv, and Maxim DL with Astro-Physics V2 drv.

Telescope
TEC APO 140

Mount
Astro-Physics Mach 1 GTO

Camera
QSI 583 WSG

Guiding
OAG guiding with Lodestar Guider

Focus system
Starlight Micro Touch and Focus MAX.


Inverted B/W image


Pure H-alpha