Thor's Helmet (NGC 2359)

clic for 50% size 1437 x 181 (750 kB)


About this Image

The colorful nebula Thor's Helmet (NGC 2359) is situated in Canis Major, very low for us northern observers. In the case of this nebula all of the power and strength is derived from the very energetic star in the center of the bubble of gas. This unusual star is classified as being "Wolf-Rayet" type and is very rare.
These stars are incredibly hot (25,000-50,000K) and expell their outer layers of gas at tremendous velocities (thousands of kilometers per second). This particular star lives in an area of the galaxy (at least 10000 light years away) that contains clouds of interstellar gas. This Wolf-Rayet star has blown a bubble of ionisized gas in its neighborhood, emitting both in blue-green (O-III) and in red color (H-alpha).
North is right.
Find a wider view of this area here.

Below you see a crop on the center of the above image in 50/100% size.

clic for 100% size 993x975 (360 kB)


Technical Details


16" cassegrain in corrected primary focus at f/3

Mount MK-100 GEM
Camera SBIG STL-11000M at -30C, internal filter wheel
Filters Astronomik Ha + RGB
Date Mar 01-02, 2005.
Location Wildon/Austria
Sky Conditions mag 5 sky, temperature -10 C,
Exposure Ha = 100 minutes (10 minute sub-exposures),
G:B = 60:60 min (10 minute sub-exposures).(
Processing Image aquisition and color combine in Maxim, image calibration, aligning, DDP in ImagesPlus;
H-alpha 80% as L and 100% as red channel, O-III not used (blurred) curves, unsharp mask, color balance in Photoshop; Noise reduction by Neatimage for dark areas;
north is right;