by Ann » Sun Jun 04, 2017 7:26 pm
neufer wrote:douglas wrote:
Really, Art? [LOL]
The Alexandria Virgaffito:
Your post evokes utter confusion on my part, although I can see one, quite farfetched, connection between the Horsehead Nebula and some 2,000-year-old donkey-head graffiti. But my response to Virgaffito is
The Flame Nebula. X-rays in purple from Chandra,
and red, green and blue infrared details from Spitzer.
I said in my previous post that Alnitak appears to be located in front of all these amazing nebulas in Orion. But apparently not, according to Wikipedia:
Wikipedia wrote:
The Flame Nebula, designated as NGC 2024 and Sh2-277, is an emission nebula in the constellation Orion. It is about 900 to 1,500 light-years away.
The bright star Alnitak (ζ Ori), the easternmost star in the Belt of Orion, shines energetic ultraviolet light into the Flame and this knocks electrons away from the great clouds of hydrogen gas that reside there. Much of the glow results when the electrons and ionized hydrogen recombine. Additional dark gas and dust lies in front of the bright part of the nebula and this is what causes the dark network that appears in the center of the glowing gas.
Hmmm. If the Flame Nebula is first and foremost an emission nebula, that doesn't explain the yellow color of the Flame. I would guess that yellow and orange light from the newborn stars inside penetrates the nebula. But apparently Alnitak plays a part, too.
The Pleiades.
Photo: Tom Wildoner.
At the center of the Flame Nebula is a cluster of newly formed stars,[2] 86% of which have circumstellar disks.[3] X-ray observations by the Chandra X-ray Observatory[4][5] show several hundred young stars, out of an estimated population of 800 stars.
A total number of 800 young stars in the Flame Nebula isn't bad. Of course,
the estimated total number of stars in the Pleiades is more than 1,000.
Ann
[quote="neufer"][quote="douglas"]
Really, Art? [LOL] :ssmile: [/quote]
The Alexandria Virgaffito:[/quote]
Your post evokes utter confusion on my part, although I can see one, quite farfetched, connection between the Horsehead Nebula and some 2,000-year-old donkey-head graffiti. But my response to Virgaffito is :?:
[float=left][img2]https://lh3.googleusercontent.com/-z-sZ1wzUXPA/VhThpT7sabI/AAAAAAAAKaw/5OygTicU5Ng/w800-h800/flame%2Bnebula.jpg[/img2][c][size=85]The Flame Nebula. X-rays in purple from Chandra,
and red, green and blue infrared details from Spitzer.[/size][/c][/float] I said in my previous post that Alnitak appears to be located in front of all these amazing nebulas in Orion. But apparently not, according to Wikipedia:
[quote][url=https://en.wikipedia.org/wiki/Flame_Nebula]Wikipedia[/url] wrote:
The Flame Nebula, designated as NGC 2024 and Sh2-277, is an emission nebula in the constellation Orion. It is about 900 to 1,500 light-years away.
The bright star Alnitak (ζ Ori), the easternmost star in the Belt of Orion, shines energetic ultraviolet light into the Flame and this knocks electrons away from the great clouds of hydrogen gas that reside there. Much of the glow results when the electrons and ionized hydrogen recombine. Additional dark gas and dust lies in front of the bright part of the nebula and this is what causes the dark network that appears in the center of the glowing gas.[/quote]
Hmmm. If the Flame Nebula is first and foremost an emission nebula, that doesn't explain the yellow color of the Flame. I would guess that yellow and orange light from the newborn stars inside penetrates the nebula. But apparently Alnitak plays a part, too.
[float=right][img2]https://s-media-cache-ak0.pinimg.com/736x/90/93/6a/90936aecce6a1de863adb0b23e3f5580.jpg[/img2][c][size=85]The Pleiades.
Photo: Tom Wildoner.[/size][/c][/float]
[quote]At the center of the Flame Nebula is a cluster of newly formed stars,[2] 86% of which have circumstellar disks.[3] X-ray observations by the Chandra X-ray Observatory[4][5] show several hundred young stars, out of an estimated population of 800 stars.[/quote]
A total number of 800 young stars in the Flame Nebula isn't bad. Of course, [url=https://en.wikipedia.org/wiki/Pleiades#Composition]the estimated total number of stars in the Pleiades[/url] is more than 1,000.
Ann