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Post by stevec on Sept 7, 2014 21:26:08 GMT -6
I discovered what caused some confusion on my part. When I first tried to open Ken's link, my tablet opened only a portion of the image, the upper 1/4. I thought the coronal hole was that light bright patch at about 12 o'clock. I never saw that dark patch at 7 o'clock. You are not looking through the sun, Ken, if that's what you were thinking. It's just an illusion created by contrasts in the x-ray spectrum. X-rays are emitted by the sun, they are not passing through the sun like you would see in an x-ray image of your hand. X-rays are considered part of the invisible light spectrum, so what you see here are holes(contrasting areas) in the x-ray spectrum of invisible light being caused by cool, dark, low density plasma vs hot, bright, high density plasma. It's the same as looking at thermal images of a human body with tne same bright and dark spots. They are not really holes in the sun's mass, they are opennings in the sun's magnetic field that allow more x-rays to escape. Think of it as similar to the hole in our ozone layer which allows more harmful UV light to pass through our atmosphere.
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Post by stevec on Sept 7, 2014 22:07:52 GMT -6
I was wrong. It's not possible to see what scientists consider coronal holes in Ha, which is the light spectrum my scope uses. You need an x-ray scope to reveal the cooler, darker, less dense plasma areas that constitute coronal holes. Though sunspots are holes, they are miniscule compared to coronal holes. The dynamics of coronal holes are not well understood, though scientists have made correlations to solar magnetic fields. Coronal holes follow openings in the sun's magnetic field. The dark area in the x-ray image below constitute what is considered coronal holes. Looks like a highly worn ancient gold coin. Quite interesting. You just might rekindle my old passion for astronomy. Were you able to click on the H-a image and make it larger? Pretty amazing, isn't it? That photo catches more surface detail, sometimes the prominences along the edge are a lot more dramatic. They're quite weak in that image. It's funny, there's a psychological/physiological effect to looking at the sun with the Ha scope in the summertime. I can stand outside in the sun, with some perspiration, no big deal, but the moment I start looking at the sun with the scope, the sweat just starts pouring from my head. Knowing about the heat being generated and viewing it in action just turns on the faucet.
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Post by woodrowli on Sept 8, 2014 12:03:42 GMT -6
Looks like a highly worn ancient gold coin. Quite interesting. You just might rekindle my old passion for astronomy. Were you able to click on the H-a image and make it larger? Pretty amazing, isn't it? That photo catches more surface detail, sometimes the prominences along the edge are a lot more dramatic. They're quite weak in that image. It's funny, there's a psychological/physiological effect to looking at the sun with the Ha scope in the summertime. I can stand outside in the sun, with some perspiration, no big deal, but the moment I start looking at the sun with the scope, the sweat just starts pouring from my head. Knowing about the heat being generated and viewing it in action just turns on the faucet. No problem unless you get a sunburn from looking at Sirius. I agree there is a sensation of feeling heat when viewing the Sun. I've only viewed through the standard filters of the 1970s or so era and even then there was a "feeling" of getting warmer.
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Post by ken on Sept 8, 2014 13:45:13 GMT -6
I was wrong. It's not possible to see what scientists consider coronal holes in Ha, which is the light spectrum my scope uses. You need an x-ray scope to reveal the cooler, darker, less dense plasma areas that constitute coronal holes. Though sunspots are holes, they are miniscule compared to coronal holes. The dynamics of coronal holes are not well understood, though scientists have made correlations to solar magnetic fields. Coronal holes follow openings in the sun's magnetic field. The dark area in the x-ray image below constitute what is considered coronal holes. The picture is breathtaking Attachments:
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Post by stevec on Sept 8, 2014 20:27:28 GMT -6
You do realized that the picture is an illusion, correct? A photographic trick?
The sun's corona(i.e. coronal) is actually the equivalent to our atmosphere. There is no hole in the sun, like I said. You're pretty much just seeing sources of x-ray emissions coming through the sun's upper atmosphere. That's not how the sun appears in visible light.
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