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N6522 & Baade's Window - are low extinction portholes rare?
An interesting question is:
"are there other fields (apart from NGC 6522/6528) where foreground extinction is so low that we can see all the way in to near the centre of our own galaxy?".
The low extinction (little foreground dust) region at and around NGC 6522 corresponds to the famous Baade's Window.
(see this preprint: astro-ph 9512137 at http//arxiv.org
and/or this reference : (1996), ApJ, 460, L37 (letters, page 37)
The stars in this low extinction window have been repeatedly studied, in order to characterize the stellar population that is found in the bulge component of the Milky Way galaxy.
(e.g. stellar ages & masses & metallicities & temperatures & colours)
It is often said that Baade's Window is one of the few places where we can view inwards to near the centre of our own Galaxy, but I wonder if this isn't just the sort of myth that becomes "truth" through constant repetition.
My own impression, from those long ago days when I was a regular night watchman of the Milky Way, was that there should be other places where we can see bulge stars.
It is not uncommon for the same incorrect information to be repeated again and again in astronomy textbooks, for instance the myth of the Milky Way being 100,000 light years across.
In fact, the region of spiral structure is only 70,000 to 80,000 light years across.
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