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Homework Help: Temperature of a star via its flux

  1. Feb 10, 2012 #1
    1. The problem statement, all variables and given/known data

    What is the temperature of a star if the flux at 450 nm is measured to be 1.3 times the flux at 650 nm

    2. Relevant equations

    To determine monochromatic flux I use:


    x= hv/kT

    3. The attempt at a solution

    So basically I plug in the 450 or 640 nm wave lengths for v and using the other constants I try to guess a temperature that when I combine the individual monochromatic fluxes, they will equal 1.3

    However I am using values from 5-50000 kelvin for my temperature, and I dont seem to be getting closer to 1.3, what am i missing?
  2. jcsd
  3. Feb 10, 2012 #2
    So ive tried this:

    v3(ehv'/kt)-1= 1.3
    (ehv/kt-1) v'3

    where as the ' notes the other wavelength..

    Also how do i turn the nm into frequency?
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