The Elephant Trunk Nebula (IC 1396A with vdB 142)

clic for 32% size 1196 x 773 (374 kB)

Clic here for 50% size 1894x2417 (924 kB)

 


About this Image

The Elephant Trunk Nebula (IC 1396A), an elongated dark cometary globule is situated within the western part of the huge IC 1396 emission complex in the constellation Cepheus. The small blue reflection nebula within the top of the trunk is named vdB 142. Located at a distance of 2,450 light-years, the globule, shown here in a false color assignment is a condensation of dense gas and dust, compressed by the surrounding ionized gas, which is barely surviving the strong ionizing radiation from a nearby massive star.
S-II is assigned to red, H-alpha to green, O-III to blue (Hubble palette).
IC 1396 covers an apparent width of more than 10 full moons, find a wider view: here.
North is to the right.

A closeup on the top of the nebula in 40/80% size in mapped color is shown below.

clic for 80% size 979 x 1181 (233 kB)


Technical Details
Optics

16" Cassegrain in secondary focus at f/10

Mount MK-100 GEM
Camera SBIG STL-11000M at -20C, 1x1 bin, internal filter wheel
Filters Astronomik Ha, O-III, S-II
Date Sep 05-25 2006.
Location Wildon/Austria
Sky Conditions mag 5 sky, good seeing, temperature 17 C
Exposure S-II:Ha:O-III =240:300:240 minutes for each of the 2-part mosaic (30-minute sub-exposures),total 26 hours
Processing Image aquisition, color synthesis in Maxim DL 4.56; calibration, aligning, stacking in CCDStack;
Photoshop: mosaic assembly; H-alpha as green channel and blended 70% as L channel, S-II as red and O-III as blue, levels and curves, color balance; noise handling by Neatimage;