|
Hi, tornado33,
In your photo, I enjoyed the sense of the dust in the Coalsack being not particularly heavy in its extinction of the background light.
A couple of papers that I once read found that even the most dense parts of the Coalsack only decrease the light of the background stars by a visual extinction of only 2 to 2.5 magnitudes.
In fact, Seidensticker and Schmidt-Kaler (1989, A&A, Volume 225, p.192) found that the average visual extinction ("dimming") caused by the dust within the Coalsack is only 0.94 magnitudes!!!
note added in edit:
I just downloaded a recent paper stating that there are a few very small spots in the Coalsack where visual extinction is 6 magnitudes, while not changing the overall picture of modest extinction for most of this dark nebula.
Last edited by madbadgalaxyman; 15-05-2012 at 10:21 AM.
Reason: correction
|