Hello Dana,
That is a very involving piece of scientific/artistic prose! I enjoyed your artistic and scientific experiment of imagining the weird sensations that come with being "trapped in the tentacles of a dark nebula".
In the same vein, I note that J.R.R. Tolkien refers to a giant spider monster as "weaving webs of shadow". Hmm, not a bad way to imagine the appearance of a dark nebula.
But, more seriously, most visual observers do not have access to your abnormally dark and transparent skies, so they must resort to using binoculars in order to increase the apparent contrast (as discerned by the "eyes + brain + mind" system) between the star-field and those inky "absences" where the line-of-sight density of the interstellar dust leads to >=2 magnitudes of dimming of the background light.
I have also found, from experience, that excellent light transmission of the optics can be an essential factor in achieving optimal viewing of dark nebulae, especially in average dark sky conditions;
so I strongly prefer using those binoculars that have the most effective anti-reflection coatings on each refracting air-glass surface and/or the highest-reflectivity mirrors
I used to use a pair of extremely-high-quality 4 inch refracting binoculars for dark nebula observations, but that was mainly due to lack of money for an even bigger pair of binoculars (!)..... ..it has always seemed to me that the dark nebula views through 5-8 inch binoculars were much better than those with 4 inch binos.
If ever did go back to regular deep sky obs, I would invest in a pair of binoculars in the aperture range 5-12 inches, as it gives you significantly increased contrast on deep sky objects, even if conditions are not absolutely optimal.
cheers,
Robert
I note that Herschel Space Observatory observed the cold dust of the Coalsack, in
emission (!!), at far-infrared wavelengths of >=250 micrometers.
Yeah, she (the Coalsack) might look inky at visible wavelengths, but she lights up like a candle in FIR:
http://starformation-herschel.iap.fr/gouldbelt/
There is a most impressive extinction map of part of the coalsack on this website:
I presented an extinction map of the Coalsack from a 1999 paper by Cambresy in this post:
http://www.iceinspace.com.au/forum/s...light=coalsack
The fundamental question is why the Coalsack has
not formed stars, yet other Very Similar molecular clouds
have formed stars.
The coalsack continues to be an unpopular subject for research, as most investigators have instead focused on those molecular clouds that
have formed stars.
One would think that the Coalsack is an important "no" case.
P.S
Dana, you may be interested in my recent posts in the Deep Sky imaging forum, relating to NGC 3621 and to the M81/M82 field.
N3621 is an excellent example of a very-extended disk of notably low optical surface brightness, in which star formation is occurring at large galactocentric radii (GALEX papers call objects like this "XUV" disks, and optical papers call them "Low Surface Brightness Disks).
The M81 field has
inter-galactic blue knots.....how did the OB stars get out there, or did they form from the HI existing between the galaxies?
Did you know that a few
elliptical galaxies also have disks with low-level star formation?!!?!