Ann wrote:The color balance seems slightly shifted to the red, apart from the fact that the blue color of the helmet is so obvious. But some of the stars look very orange, while none of the stars look strikingly blue. Nevertheless, some of the stars do display a faint bluish color, and many of the stars look white, so the color balance for the stars isn't that far off. The most orange one of the stars, to the upper right of the helmet, probably is very red for real.
"Color balance" doesn't mean anything in this image, because it was produced through filters that don't mimic the response of the eye. The image is a hybrid of conventional RGB (which does approximate the eye's response) along with OIII and Ha. The OIII signal was assigned to the green and blue output channels, and Ha to red. This will obviously produce something quite unlike "true" color.
The red "horns" of the helmet are obviously glowing red from ionized hydrogen. It is interesting that the red "arc" at lower right and the red patch at lower left are a much duller red color, particularly the "arc". Could the arc be dust-reddened, and if so, could it be more dust-reddened than the "horns"? No, it looks more like a mixture of red emission nebulosity, blue reflection nebulosity and some unlit dust, all pretty much mixed up and muted-looking.
Those areas look redder to me. That is, they appear to be closer to a single channel signal, while the upper areas have some signal from green and blue. The only reason the lower areas look "duller" is because they are darker. Dark pure red will look dull compared to a brighter mix of red and other colors. The only really obvious dust I see is just below the bubble itself.
The bubble itself is very blue from oxygen emission. It's interesting that it contains no red nebulosity at all. The reason must be that the bubble contains no hydrogen at all. The outer hydrogen shell has been blown off, and the remnants are seen as the red "horns" of the helmet.
It may contain hydrogen in other states of ionization, or neutral. Those would not show up as red in this image.
The bubble is richly textured, and I have no idea why that is so. Could it possibly have anything at all to do with magnetism?
It may, in part, be due to the magnetic properties of the star that threw the material off. But it is probably also a fluid dynamic effect, caused by turbulence. Filaments like this are easily created by many different forces. Magnetic fields are suggested to maintain large filamentary structures against destruction by stellar winds. That isn't happening here- the bubble is dissipating and the filaments are evaporating. In a few thousand years this object will be gone.
Thor s Helmet
When you click on the picture; and get the smaller view; it looks a lot better to me. 
The original overfills my computer screen anyway. 
