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Spectrum of the Sun

  1. Jan 24, 2014 #1
    Is the rather continuous spectrum of the Sun due to redshift/blueshift of the radiation emenating from the Sun? I understand that the emission spectrum of Hydrogen in the visible range is quantized to four discrete values, but I'm trying to understand how all frequencies of visible light are available for us to use.
     
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  3. Jan 24, 2014 #2

    Bill_K

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    Light is produced in many ways besides the excitation of individual atomic spectral lines. For example it can be produced when atoms collide. Quoting Wikipedia,

     
  4. Jan 25, 2014 #3

    UltrafastPED

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    The sun can be treated as a blackbody ... it is a very hot body, and thus emits radiation following the blackbody spectrum.

    You can see definite lines in the solar spectrum; these are well explained here:
    http://www.astro.washington.edu/courses/labs/clearinghouse/labs/Solarspec2/sunspec.html [Broken]
     
    Last edited by a moderator: May 6, 2017
  5. Jan 25, 2014 #4

    edguy99

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    NIST data (http://www.nist.gov/pml/data/asd.cfm) give Solar Hydrogen Spectral Lines intensity in terms of energy: 250,000@12.09eV, 840,000@10.20eV, 90,000@2.86eV, 180,000@2.55, 500,000@1.89eV. The 1.89 eVolt energy is the most common one we can see.

    We see all sorts of other photon energies that are generated since the hydrogen on the sun surface is moving around. If the hydrogen atom is moving away from us, we will see a photon with less than 1.89eV (red shifted), if moving towards us, it will have more than 1.89eV energy (blue shifted)
     
  6. Jan 25, 2014 #5

    Bill_K

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    No. As pointed out above, this is absolutely not the explanation. Doppler broadening of the spectral lines is present, but much too small to produce a continuous spectrum. And the majority of the photons are produced in other ways, simply from the thermal motion of the atoms.
     
    Last edited: Jan 25, 2014
  7. Jan 25, 2014 #6

    edguy99

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    Thank you for the correction, I agree the thermal motion is the most important.
     
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