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Annular Eclipse Ambient Light Wavelength Shift Due To Limb Color

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#1 foxwoodastronomy

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Posted 17 November 2023 - 06:48 AM

You folks are going to love this! In 2017, I saw the amazing change to the gray/silvery character of light/color that occurs in the surroundings about 5 minutes before totality. I wanted to study this effect more during the 2019 total solar eclipse, so I did a basic spectral analysis of the Sun by pointing a spectrum data logger at the Sun. At the 2023 annular eclipse, I pointed the spectrum data logger at the observing position, and the data is even more interesting than in 2019. Follow the three images. #1 It is known that the limb of the Sun is a different color than the center of the Sun. With an entire solar disk, the color of the center of the Sun overwhelms the contribution of the limb of the Sun #2 I questioned what happens to the observer's ambient lighting late in the partial phases when the crescent limb of the Sun is illuminating us? It turns out that the wavelengths of light coming to Earth change. I measured it in 2019 and again in 2023 at the annular eclipse. But the annular is fascinating because there is no totality, just a long time being lit by the limb color! #3 The observer is lit by a different percentage of the three wavelengths of light with a shift to the red because most of the Sun's surface, which has a color around 6,300K, is blocked, leaving us to be illuminated by the limb. I don't have an explanation for the two blue spikes that occurred about 15 minutes before C2 and after C3. So, in addition to a decrease in LUX, this wavelength change may contribute to the fact that some observers saw a difference in the character of the lighting during annularity. This wavelength shift is interesting, but at a total solar eclipse, the more powerful effect regarding the ambient lighting color changes is the biochemistry of the Purkinje Effect.

Attached Thumbnails

  • #1 sun with Kelvin new ref 600 px CN.jpg
  • #2 two kelvin image what happens on earth 600 px CN.jpg
  • #3 full data color specrum graph 100 px  CN.jpg

  • RNSpeed, rockethead26 and Bob W4 like this

#2 timelapser

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Posted 29 November 2023 - 03:17 PM

It seems this thread was duplicated in the Other Eclipses forum.  Some questions have been asked there but maybe it's better to reply there...


Edited by timelapser, 29 November 2023 - 08:43 PM.



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