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Astronomy Picture of the Day 12-13-02
NASA ^ | 12-13-02 | Robert Nemiroff and Jerry Bonnell

Posted on 12/13/2002 3:53:12 AM PST by petuniasevan

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2002 December 13
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

The Crown of the Sun
Credit & Copyright: (C2002) Wendy Carlos & Jonathan Kern (all rights reserved)

Explanation: During a total solar eclipse, the Sun's extensive outer atmosphere or corona is an awesome and inspirational sight. Yet the subtle shades and shimmering features of the corona that engage the eye span a brightness range of over 10,000 to 1, making them notoriously difficult to capture in a photograph. Still, this single five second exposure comes very close to revealing the crown of the Sun in all its glory. The color picture was taken with a specially built coronal camera and telescope during the December 4th total eclipse from Messina, South Africa. The camera's design incorporates a precisely made filter whose density, or ability to block light, decreases markedly with distance from the filter center, compensating for the difference between the brighter inner portion of the corona at the Sun's edge and the much fainter outer regions. The central spot in the image corresponds to a calibration window centered on the eclipsed Sun.


TOPICS: Astronomy; Astronomy Picture of the Day; Science
KEYWORDS: camera; corona; eclipse; exposure; filter; photo; photography; solar; study; sun; telescope; total
This is a unique photo; the camera used is specially built just for eclipse photography.

Good morning all!

1 posted on 12/13/2002 3:53:12 AM PST by petuniasevan
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To: MozartLover; Joan912; NovemberCharlie; snowfox; Dawgsquat; viligantcitizen; theDentist; ...

2 posted on 12/13/2002 3:54:17 AM PST by petuniasevan
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To: petuniasevan
Mornin' !!


Have a cup while you FReep !

3 posted on 12/13/2002 4:22:52 AM PST by MeekOneGOP
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To: petuniasevan
Good morning & thank you
4 posted on 12/13/2002 4:47:03 AM PST by firewalk
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To: petuniasevan
Beautiful! I always love eclipse photos...
5 posted on 12/13/2002 4:55:41 AM PST by GodBlessRonaldReagan
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To: petuniasevan
Thank you!
6 posted on 12/13/2002 6:24:33 AM PST by foolish-one
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To: petuniasevan
That is one interesting image -- thanks!
(somewhat reminiscent of a recent opthalmologist visit ;^)
7 posted on 12/13/2002 7:04:12 AM PST by mikrofon
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To: petuniasevan
I was wondering, why do they only use this camera during an eclipse? Wouldn't the calibration dot in the center of the pic give the same effect as an eclipse?
8 posted on 12/13/2002 8:21:06 AM PST by WSGilcrest
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To: WSGilcrest
Wouldn't the calibration dot in the center of the pic give the same effect as an eclipse?

It would work fine outside the atmosphere.

9 posted on 12/13/2002 12:20:33 PM PST by RightWhale
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To: RightWhale; WSGilcrest
RightWhale is right. If you try blocking the sun with your hand you'll see that the glare (Mie scattering) and blue sky (Rayleigh scattering) hide the corona.

Without the atmosphere in the way, there would be no such difficulty. Orbiting satellites such as SOHO study the sun's corona by blocking the disk. Here's a LASCO image from SOHO:


10 posted on 12/13/2002 1:04:12 PM PST by petuniasevan
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To: petuniasevan
Interesting. Thanks.
11 posted on 12/13/2002 5:25:41 PM PST by sistergoldenhair
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