APOD: Sun and Prominence (2014 Mar 04)

Comments and questions about the APOD on the main view screen.
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APOD: Sun and Prominence (2014 Mar 04)

Post by APOD Robot » Tue Mar 04, 2014 5:13 am

Image Sun and Prominence

Explanation: Dramatic prominences can sometimes be seen looming just beyond the edge of the sun. Such was the case last week as a large prominence, visible above, highlighted a highly active recent Sun. A waving sea of hot gas is visible in the foreground chromosphere in great detail as it was imaged in one specific color of light emitted by hydrogen. A solar prominence is a cloud of solar gas held just above the surface by the Sun's magnetic field. The Earth, illustrated in the inset, is smaller than the prominence. Although very hot, prominences typically appear dark when viewed against the Sun, since they are slightly cooler than the photosphere below them. A quiescent prominence typically lasts about a month, and may erupt in a Coronal Mass Ejection (CME) expelling hot gas into the Solar System, some of which may strike the Earth and trigger auroras.

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Boomer12k » Tue Mar 04, 2014 6:52 am

Yup...their BIG!!!

Nice comparison...
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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by starsurfer » Tue Mar 04, 2014 8:26 am

Hooray for Coronal Mass Ejections! :D :D :D

Czerno 1

Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Czerno 1 » Tue Mar 04, 2014 10:45 am

Cool :=)
Comments say a prominence would appear less bright than the sun's surface.
I don't quite see it thusly looking at this photograph : is it a negative ?

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by neufer » Tue Mar 04, 2014 1:59 pm

Czerno 1 wrote:Cool :=)
Comments say a prominence would appear less bright than the sun's surface.
I don't quite see it thusly looking at this photograph : is it a negative ?
No. You are just comparing it against the dark background of space.

When compared against the solar surface like a sunspot it becomes a dark cool filament:
http://www.thesuntoday.org/overview/objects-on-and-from-the-sun/ wrote: _The Sun Today_ by C. Alex Young, Ph.D.

<<Sometimes magnetic field in the solar atmosphere holds up solar plasma from the chromosphere into the solar corona. The filaments are held up in a kind-of magnetic hammock. The relatively cool filament material appears dark when observed against the bright solar disk. Filaments can stretch far across the Sun measuring 100s of thousands of kilometers. The equivalent of 10 or more Earths lined up in a row. Prominences are really just the same thing as filaments only viewed from a different perspective. Filament are seen on the solar disk however filament are very high up in the solar atmosphere, way above the surface. So when a filament is on the edge of the Sun the filament sticks out with space instead of the solar surface behind it. This makes the filament very bright compared to the dark (cold) background of space. We call a filament viewed this way a prominence. They can be simple looped shaped object or very irregular with a complicated structure.>> More at:
http://www.thesuntoday.org/overview/obj ... m-the-sun/
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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Chris Peterson » Tue Mar 04, 2014 3:17 pm

Czerno 1 wrote:Comments say a prominence would appear less bright than the sun's surface.
I don't quite see it thusly looking at this photograph : is it a negative ?
The difference in brightness isn't normally very large. In this case, we are seeing the prominence adjacent to the limb darkened edge, making the two have nearly identical average intensities. The difference would be more apparent if this were seen as a filament in a central section of the Sun.
Chris

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Ann » Tue Mar 04, 2014 3:34 pm

APOD Robot wrote:
Tomorrow's picture: colorful space chicken
Could it possibly be the Running Chicken Nebula? But which chicken?

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Psnarf » Tue Mar 04, 2014 4:28 pm

I did not know that those beasties were above the solar surface in the photosphere, like a layer of clouds, or that different gasses could change layers. The granulation around a sunspot in the photosphere suggests that there may be another layer below that. Somewhere among the related sites listed below describes how the filaments are frozen to magnetic field lines.

Dr. Feynman suggests that magnetic fields are streams of low-energy photons. I guess Faraday was right when he thought of magnetic field lines of force indicating the direction and strength of the magnetic field at a given point. If you sprinkle iron filings on a paper over a magnet, they line up along those field lines; if you repeat the process, taking a photograph of the iron filings each time, would the lines pretty-much line up, or would they trace a different path each time. Sans a bar magnet and filings, I can only wonder. [Disclaimer: homophone of Zanzibar unintentional and not meant to irritate the residents of Tanzania]

http://sdo.gsfc.nasa.gov/mission/instruments.php
http://sdo.gsfc.nasa.gov/data/
http://aia.lmsal.com/public/CSR.htm

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Psnarf » Tue Mar 04, 2014 4:30 pm

[Delete this before reading it.] Why did the space chicken cross the nebula?

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by wroberts » Tue Mar 04, 2014 4:33 pm

The inset photo of the earth should have been delineated more prominently. Less knowledgeable viewers or those who fail to read the caption might incorrectly assume this is an actual photo of the Sun and Earth rather than a composite.

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Chris Peterson » Tue Mar 04, 2014 4:36 pm

Psnarf wrote:Dr. Feynman suggests that magnetic fields are streams of low-energy photons.
That's not the case. Feynman utilized the concept of virtual photons as force carriers describing magnetic fields. Magnetic fields are not created by streams of photons, and I don't think Feynman ever made that suggestion.
Chris

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Chris Peterson » Tue Mar 04, 2014 4:39 pm

wroberts wrote:The inset photo of the earth should have been delineated more prominently. Less knowledgeable viewers or those who fail to read the caption might incorrectly assume this is an actual photo of the Sun and Earth rather than a composite.
Personally, I have very little sympathy for people who misunderstand images because they're too lazy to read the caption. It is much easier to get a sense of scale without any delineation. (And I think the fact that one image is color and the other B&W gives a bit of a clue, as well.)
Chris

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Anthony Barreiro » Tue Mar 04, 2014 8:01 pm

Chris Peterson wrote:
wroberts wrote:The inset photo of the earth should have been delineated more prominently. Less knowledgeable viewers or those who fail to read the caption might incorrectly assume this is an actual photo of the Sun and Earth rather than a composite.
Personally, I have very little sympathy for people who misunderstand images because they're too lazy to read the caption. It is much easier to get a sense of scale without any delineation. (And I think the fact that one image is color and the other B&W gives a bit of a clue, as well.)
But there should be a prominent disclaimer: if the Earth were at this distance from the Sun, it would no longer be in the Sun's habitable zone, and would no longer have oceans or clouds. :lol2:
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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by LocalColor » Tue Mar 04, 2014 11:10 pm

A stunning and very informative image.

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Chris Peterson » Wed Mar 05, 2014 12:05 am

Anthony Barreiro wrote:But there should be a prominent disclaimer: if the Earth were at this distance from the Sun, it would no longer be in the Sun's habitable zone, and would no longer have oceans or clouds.
Nonsense. It's in exactly the middle of the habitable zone for plasma fish.
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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Beyond » Wed Mar 05, 2014 1:02 am

:)))))))))))))))))))))
To find the Truth, you must go Beyond.

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Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Anthony Barreiro » Wed Mar 05, 2014 3:40 am

Chris Peterson wrote:
Anthony Barreiro wrote:But there should be a prominent disclaimer: if the Earth were at this distance from the Sun, it would no longer be in the Sun's habitable zone, and would no longer have oceans or clouds.
Nonsense. It's in exactly the middle of the habitable zone for plasma fish.
Oh yes, of course. I read about them in The Journal of Exobiology.
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Czerno 1

Re: APOD: Sun and Prominence (2014 Mar 04)

Post by Czerno 1 » Sat Mar 08, 2014 10:36 am

Belated thanks (Neufer, Chris!) for explanations re. relative brilliance,
and the fact that prominences and filaments are the same phenomenon,
just different views ! Very instructive...