Cave Nebula in H-alpha (SH2-155)

clic for 32% size 1200 x 811 (298 kB)

Clic here for 50% size 1956x1322 (681 kB)


About this Image

The Cave Nebula is an extended H-alpha area situated the constellation Cepheus at a distance of 2,400 light years. It is surrounded by very dim structures shaped by the pressure of the surrounding stars. The brightest star in the center is mag 6.5 SAO 20328.
North is right.

A closeup on the Cave in 42/70% size is shown below.

clic for 70% size 846 x 844 (150 kB)

Technical Details


16" Cassegrain in corrected prime focus at f/3

Mount MK-100 GEM
Camera SBIG STL-11000M at -15C, 1x1 bin, internal filter wheel
Filters Astronomik Ha,
Date Sep 02 2005.
Location Wildon/Austria
Sky Conditions mag 4.5 sky, low transparency, temperature 22 C
Exposure Ha = 150 minutes (30-minute sub-exposures),
Processing Image aquisition, calibration, aligning, stacking in Maxim DL 4.11;
Photoshop: levels and curves, light unsharp mask; little noise reduction by Neatimage;