Comments and questions about the
APOD on the main view screen.
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APOD Robot
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by APOD Robot » Sat Jan 28, 2017 5:40 am
N159 in the Large Magellanic Cloud
Explanation: Over 150 light-years across, this
cosmic maelstrom of gas and dust is not too far away. It lies south of the Tarantula Nebula in our satellite galaxy the
Large Magellanic Cloud a mere 180,000 light-years distant. Massive stars have formed within. Their energetic radiation and powerful stellar winds sculpt the gas and dust and power the glow of this
HII region, entered into the
Henize catalog of emission stars and nebulae in the Magellanic Clouds as N159. The bright, compact, butterfly-shaped nebula above and left of center likely contains massive stars in a very early stage of formation.
Resolved for the first time in Hubble images, the compact blob of ionized gas has come to be known as the Papillon Nebula.
[/b]
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Ann
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by Ann » Sat Jan 28, 2017 7:11 am
N159 in the LMC. NASA,ESA, Hubble Space Telescope.
M78 in Orion. Photo: ESO/Igor Chekalin.
What I like best about today's APOD is the blue nebula with a curved dust lane partly framing it in the lower right corner of the photo.
This nebula looks like a massively scaled-up and extremely hot version of reflection nebula M78 in Orion!
Ann
Color Commentator
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Boomer12k
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by Boomer12k » Sat Jan 28, 2017 8:12 am
Awesome... looks like another Trifid Nebula on the far right...
I want to become a wispy cloud in a dusty nebula....
:---[===] *
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CharlesE
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by CharlesE » Sat Jan 28, 2017 12:52 pm
The description states the nebula is a "mere 180,000 light years away." It is rather awesome to realize that time interval is 90 times our recorded history!
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smitty
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by smitty » Sat Jan 28, 2017 1:42 pm
Am I mistaken in wondering whether the bright butterfly-shaped nebula is below and right of center rather than above and left of center? Perhaps the image was inverted?
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De58te
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by De58te » Sat Jan 28, 2017 1:46 pm
Re: Charles E, Actually it is 60 times or recorded history if you think Homer is the first Greek historian. 40 times if you think the first hieroglyphs were written in the Step Pyramid of Djoser, or 36 times if you think recorded history started with the Sumerian's Cuneiform writing of about 3,000 B.C.
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neufer
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by neufer » Sat Jan 28, 2017 2:02 pm
De58te wrote:CharlesE wrote:
The description states the nebula is a "mere 180,000 light years away." It is rather awesome to realize that time interval is 90 times our recorded history!
Actually it is 60 times or recorded history if you think Homer is the first Greek historian. 40 times if you think the first hieroglyphs were written in the Step Pyramid of Djoser, or 36 times if you think recorded history started with the Sumerian's Cuneiform writing of about 3,000 B.C.
https://en.wikipedia.org/wiki/History wrote:
<<History (from Greek ἱστορία, historia, meaning "inquiry, knowledge acquired by investigation") is the study of the past as it is described in written documents. Stories common to a particular culture, but not supported by external sources (such as the tales surrounding King Arthur), are usually classified as cultural heritage or legends, because they do not show the "disinterested investigation" required of the discipline of history. Herodotus, a 5th-century BC Greek historian is considered within the Western tradition to be the "father of history", and, along with his contemporary Thucydides, helped form the foundations for the modern study of human history. In Asia, a state chronicle, the Spring and Autumn Annals was known to be compiled from as early as 722 BC although only 2nd-century BC texts survived.>>
Art Neuendorffer
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Chris Peterson
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by Chris Peterson » Sat Jan 28, 2017 3:00 pm
CharlesE wrote:The description states the nebula is a "mere 180,000 light years away." It is rather awesome to realize that time interval is 90 times our recorded history!
A light year is not a time interval. Perhaps you mean that the light required many times the length of our recorded history to reach us. (I would have said that the light reaching us now was emitted just as anatomically modern humans first developed.)
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Chris Peterson
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by Chris Peterson » Sat Jan 28, 2017 3:01 pm
Boomer12k wrote:I want to become a wispy cloud in a dusty nebula....
Good news! That is the destiny that awaits all of us.
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ta152h0
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by ta152h0 » Sat Jan 28, 2017 3:13 pm
Caramba, que coisa bonita
Wolf Kotenberg
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neufer
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by neufer » Sat Jan 28, 2017 4:46 pm
Chris Peterson wrote:CharlesE wrote:
The description states the nebula is a "mere 180,000 light years away."
It is rather awesome to realize that time interval is 90 times our recorded history!
A light year is not a time interval.
Perhaps you mean that the light required many times the length of our recorded history to reach us.
Han Solo:
Chewie here tells me you're lookin' for passage to the Alderaan system?
Ben Obi-Wan Kenobi:
Yes indeed, if it's a fast ship.
Han Solo:
Fast ship? You've never heard of the Millennium Falcon?
Ben Obi-Wan Kenobi:
Should I have?
Han Solo:
It's the ship that made the Kessel Run in less than twelve parsecs.
Chris Peterson wrote:
(I would have said that the light reaching us now was emitted just as anatomically modern humans first developed.)
https://en.wikipedia.org/wiki/Anatomically_modern_human#Evolution wrote:
<<The genus Homo emerges from australopithecine hominins some time after 3 million years ago. With the arrival of Homo erectus in the fossil record ca. 1.8 to 1.3 million years ago, cranial capacity had doubled to 850 cm3. It is believed that Homo erectus and Homo ergaster were the first to use fire and complex tools.
Modern humans evolved from Homo heidelbergensis, Homo rhodesiensis or Homo antecessor and, some 100,000 to 50,000 years ago, took the place of local populations of Homo erectus.>>
Art Neuendorffer
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alcor
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by alcor » Sat Jan 28, 2017 7:15 pm
The rays coming from the bright stars differ between separate parts of the image. The bright stars to the two thirds left have have rays going exactly horizontal and vertical ray. While the bright stars to the extreme right have rays slanting about 30 degrees to the rest. How could it differ so much between different parts of the image? Or is it human addition al a paintbox?
Arne
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Chris Peterson
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by Chris Peterson » Sat Jan 28, 2017 7:30 pm
alcor wrote:The rays coming from the bright stars differ between separate parts of the image. The bright stars to the two thirds left have have rays going exactly horizontal and vertical ray. While the bright stars to the extreme right have rays slanting about 30 degrees to the rest. How could it differ so much between different parts of the image? Or is it human addition al a paintbox?
The ACS camera natively shoots square images that are 3.4 arcminutes on a side. This image is 2.9 x 4.8 arcminutes, so it is constructed from at least two separately collected images. It isn't uncommon in mosaics for the orientation between the telescope and the sky to be different for different tiles.
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geckzilla
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by geckzilla » Sat Jan 28, 2017 10:01 pm
Chris Peterson wrote:alcor wrote:The rays coming from the bright stars differ between separate parts of the image. The bright stars to the two thirds left have have rays going exactly horizontal and vertical ray. While the bright stars to the extreme right have rays slanting about 30 degrees to the rest. How could it differ so much between different parts of the image? Or is it human addition al a paintbox?
The ACS camera natively shoots square images that are 3.4 arcminutes on a side. This image is 2.9 x 4.8 arcminutes, so it is constructed from at least two separately collected images. It isn't uncommon in mosaics for the orientation between the telescope and the sky to be different for different tiles.
This might help anyone else wondering about this. It's not the same image, but it shows the edges of different frames and how the diffraction spikes can end up going all different directions.
http://geckzilla.com/astro/LDN_1641N_uncropped.jpg
Just call me "geck" because "zilla" is like a last name.
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alter-ego
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by alter-ego » Sun Jan 29, 2017 12:01 am
geckzilla wrote:Chris Peterson wrote:alcor wrote:The rays coming from the bright stars differ between separate parts of the image. The bright stars to the two thirds left have have rays going exactly horizontal and vertical ray. While the bright stars to the extreme right have rays slanting about 30 degrees to the rest. How could it differ so much between different parts of the image? Or is it human addition al a paintbox?
The ACS camera natively shoots square images that are 3.4 arcminutes on a side. This image is 2.9 x 4.8 arcminutes, so it is constructed from at least two separately collected images. It isn't uncommon in mosaics for the orientation between the telescope and the sky to be different for different tiles.
This might help anyone else wondering about this. It's not the same image, but it shows the edges of different frames and how the diffraction spikes can end up going all different directions.
http://geckzilla.com/astro/LDN_1641N_uncropped.jpg
Even for a single star within an image, I've seen multi-colored, clocked diffraction spikes resulting from different scope orientations for the different spectral filters.
A pessimist is nothing more than an experienced optimist
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geckzilla
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by geckzilla » Sun Jan 29, 2017 12:32 am
alter-ego wrote:Even for a single star within an image, I've seen multi-colored, clocked diffraction spikes resulting from different scope orientations for the different spectral filters.
Yep. Same reason for that. Telescope was simply at a different orientation for one or more of the exposures required to create a color image.
Just call me "geck" because "zilla" is like a last name.
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Cousin Ricky
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by Cousin Ricky » Sun Jan 29, 2017 4:49 am
neufer wrote:Chris Peterson wrote:
(I would have said that the light reaching us now was emitted just as anatomically modern humans first developed.)
https://en.wikipedia.org/wiki/Anatomically_modern_human#Evolution wrote:
<<The genus Homo emerges from australopithecine hominins some time after 3 million years ago. With the arrival of Homo erectus in the fossil record ca. 1.8 to 1.3 million years ago, cranial capacity had doubled to 850 cm3. It is believed that Homo erectus and Homo ergaster were the first to use fire and complex tools.
Modern humans evolved from Homo heidelbergensis, Homo rhodesiensis or Homo antecessor and, some 100,000 to 50,000 years ago, took the place of local populations of Homo erectus.>>
That's the most recent estimate I've ever seen from anyone who isn't a young-Earth creationist.
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neufer
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by neufer » Sun Jan 29, 2017 5:20 am
Cousin Ricky wrote:neufer wrote:Chris Peterson wrote:
(I would have said that the light reaching us now was emitted just as anatomically modern humans first developed.)
https://en.wikipedia.org/wiki/Anatomically_modern_human#Evolution wrote:
<<The genus Homo emerges from australopithecine hominins some time after 3 million years ago. With the arrival of Homo erectus in the fossil record ca. 1.8 to 1.3 million years ago, cranial capacity had doubled to 850 cm3. It is believed that Homo erectus and Homo ergaster were the first to use fire and complex tools.
Modern humans evolved from Homo heidelbergensis, Homo rhodesiensis or Homo antecessor and, some 100,000 to 50,000 years ago, took the place of local populations of Homo erectus.>>
That's the most recent estimate I've ever seen from anyone who isn't a young-Earth creationist.
Young-Earth creationists have never seen N159 in the Large Magellanic Cloud.
Art Neuendorffer
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Chris Peterson
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by Chris Peterson » Sun Jan 29, 2017 5:23 am
Cousin Ricky wrote:neufer wrote:Chris Peterson wrote:
(I would have said that the light reaching us now was emitted just as anatomically modern humans first developed.)
https://en.wikipedia.org/wiki/Anatomically_modern_human#Evolution wrote:
<<The genus Homo emerges from australopithecine hominins some time after 3 million years ago. With the arrival of Homo erectus in the fossil record ca. 1.8 to 1.3 million years ago, cranial capacity had doubled to 850 cm3. It is believed that Homo erectus and Homo ergaster were the first to use fire and complex tools.
Modern humans evolved from Homo heidelbergensis, Homo rhodesiensis or Homo antecessor and, some 100,000 to 50,000 years ago, took the place of local populations of Homo erectus.>>
That's the most recent estimate I've ever seen from anyone who isn't a young-Earth creationist.
The Omo specimen is considered an anatomically modern human-
homo sapiens- and is about 200,000 years old. There were several different human species around for another 150,000 years or more after that.
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dlw
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by dlw » Sun Jan 29, 2017 6:59 pm
Ann wrote:
What I like best about today's APOD is the blue nebula with a curved dust lane partly framing it in the lower right corner of the photo.
This nebula looks like a massively scaled-up and extremely hot version of reflection nebula M78 in Orion!
Ann
I quite agree. It appears to have 2 very massive and hot stars in a cavity with lots of interesting surrounding features.
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neufer
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by neufer » Mon Jan 30, 2017 2:46 am
Chris Peterson wrote:
The Omo specimen is considered an anatomically modern human- homo sapiens- and is about 200,000 years old. There were several different human species around for another 150,000 years or more after that.
https://en.wikipedia.org/wiki/Omo_Kibish_Formation wrote:
<<The Omo Kibish Formation or simply
Kibish Formation is an East African rock formation. It is named after the archaeological site of Omo Kibish on the Omo River in Ethiopia, where it was first studied. It and its neighbouring sites have produced some of the earliest examples of fossilised human and australopithecine remains and stone tools. Richard Leakey's work there in 1967 found some of the oldest remains of primitive Homo sapiens. Earlier believed to be around 125,000 years old, more recent research indicates they may in fact date to c.195,000 years ago.>>
Art Neuendorffer