The Light, the Dark, and the Dusty
Image Credit & Copyright: Gábor Galambos
That's funny, Rauf!
For myself, I'm going to identify a few stars around the Cave Nebula and try to see what's going on here.
I used a pretty small font size, so you may want to look at the full size of the picture.
A few notes. There are three O-type stars and one star of spectral class B0.5 here, so there is no shortage of ultraviolet light in the area. The prominent red star is a foreground object - phew! I wondered how it was possible that such a very young - yes, very young and dusty! - region of star formation could host such a large cool evolved star square in the midst of the action. But indeed, it is a foreground object.
One object that made me scratch my head in the APOD is the blue reflection nebula at upper left. What's so special about that little nebula, you may ask, and indeed, it didn't look very special to me at all - until I tried to identify it! I
think we are talking about a star called TYC 4282-861-1, and its nebula. But look at what the nebula looks like in Simbad's Astronomical Database:
It's yellow!!!!
Some of you may remember that I complained about how the intrinsically blue and apparently white-colored WR 7 was shown as orange in
yesterday's APOD. Well, today we seem to have the opposite situation - a yellow reflection nebula is shown as blue! As the Color Commentator, I must disapprove not only of "the undeserved oranges" but of "the false blues", too.
Oh well. The "cave" of the Cave Nebula is interesting. It appears to be a dusty pillar, possibly a so called cometary globule, perhaps similar to the Dark Tower in Scorpius.
Note how different the Cave Nebula region looks in Carlos Uriarte's image compared with with the APOD. North is up in Carlos Uriarte's image, unlike the APOD, where south is up. Also, unlike the APOD, Uriarte has brought out lots and lots of red hydrogen alpha in his image. But in the APOD, where the red color is generally much more subdued, we can see the thin red arc that apparently gave this nebula its name.
Wikipedia wrote:
The name "Cave Nebula" was coined for this object by Patrick Moore, presumably derived from photographic images showing a curved arc of emission nebulosity corresponding to a cave mouth.
One final note. When I was searching for a suitable picture of the Dark Tower in Scorpius to post here, I came across
this Starship Asterisk* thread discussing the APOD of July 15, 2021. Both Neufer and Orin Stepanek made posts here.
I miss them.
Ann
The Light, the Dark, and the Dusty
