by Ann » Fri Oct 20, 2017 8:15 am
Today's APOD is very beautiful.
I've wondered for a long time if that bright yellow star sitting in the middle of the blue reflection nebulosity might have anything to do with that extended blue light. The star, HD 164514, is an F5-type star, and it appears to be distant, which suggests it is intrinsically bright. If it is indeed distant, so that it is a bright F5-type star, it will emit a lot of blue light. The star appears to be reddened, which would be the case if a lot of its blue light had been scattered by dust.
But the blue reflection nebula doesn't appear to be particularly bright in the immediate vicinity of the star, so I don't know if the star and the reflection nebula are connected. The question is, if the star and the reflection nebula are not connected, what would be the cause of that large reflection nebula?
In his book
A View of the Universe, David Malin could show a faint blue rim of reflection nebulosity around the otherwise very red Lagoon Nebula. The same effect can be seen in
this 1.7 MB picture of the Lagoon and the Trifid by Éder Iván. It's a beautiful picture, but you should look at it at your own risk.
But the blue rim around the Lagoon is very faint and narrow, while the blue reflection nebula north of the red Trifid Nebula is relatively bright and very extended. These two reflection nebulas can't be caused by the same mechanism.
I like your picture, Boomer!
Ann
Today's APOD is very beautiful.
I've wondered for a long time if that bright yellow star sitting in the middle of the blue reflection nebulosity might have anything to do with that extended blue light. The star, HD 164514, is an F5-type star, and it appears to be distant, which suggests it is intrinsically bright. If it is indeed distant, so that it is a bright F5-type star, it will emit a lot of blue light. The star appears to be reddened, which would be the case if a lot of its blue light had been scattered by dust.
But the blue reflection nebula doesn't appear to be particularly bright in the immediate vicinity of the star, so I don't know if the star and the reflection nebula are connected. The question is, if the star and the reflection nebula are not connected, what would be the cause of that large reflection nebula?
In his book [i]A View of the Universe[/i], David Malin could show a faint blue rim of reflection nebulosity around the otherwise very red Lagoon Nebula. The same effect can be seen in [url=http://www.astroeder.com/rimg/92/368_1314_298649fe_m8-20_ederL.jpg]this [b][size=120]1.7 MB[/size][/b] picture[/url] of the Lagoon and the Trifid by Éder Iván. It's a beautiful picture, but you should look at it at your own risk.
But the blue rim around the Lagoon is very faint and narrow, while the blue reflection nebula north of the red Trifid Nebula is relatively bright and very extended. These two reflection nebulas can't be caused by the same mechanism.
I like your picture, Boomer! :D
Ann