Quote:
Originally Posted by DavidTrap
It's certainly an impressive expanse.
Why is the monatomic hydrogen in this long exposure showing up in the green part of the spectrum. Normally hydrogen is seen towards the red end of the spectrum - Hydrogen Alpha line. If this area of hydrogen were so faint, why would it now preferentially show up as green, rather than red?
I had a look at the original 15Mb images he posted. There is some red haziness around the LMC & SMC which I thought would be the hydrogen?
Could the green be an artefact from the HDR process?
DT
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The very dim unresolved stars show up as a faint green with HDR and DSLR's as DSLR's have twice as many green pixels as red or blue. If it was light pollution it would be far more uniform. I will dig up a radio image of monatomic Hydrogen and superimpose it. When galaxies interact gravitationally both stars and Hydrogen and dust etc are all drawn out together.
Here is an image of the LMC taken by Hiro with a 105mm lens at f/5.6 that I enhanced to show the dim stuff. 13MB
http://d1355990.i49.quadrahosting.co...ol_easyHDR.jpg
Original thread here
http://www.cloudynights.com/ubbthrea.../o/all/fpart/1
It is obvious from this image that the LMC used to be a barred spiral galaxy. It has been 'Auntie Jacked' ie had its arms ripped off gravitationally. This has also caused the intense star formation we see today.
Bert