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Binary stars apparent and absolute magnitudes

  1. Nov 20, 2011 #1
    1. The problem statement, all variables and given/known data
    A binary star system has two star of equal luminosity. The apparent magnitude of the two stars together is 11.2, and they are at a distance is 76pcs. How do I work out the apparent and absolute magnitudes of just one star?


    2. Relevant equations

    m=-2.5log(L)

    m-M=5log(d)-5

    M=-2.5log(L/Lsun)+4.8



    3. The attempt at a solution

    luminosities can be added, I know that much.
     
  2. jcsd
  3. Nov 20, 2011 #2

    phyzguy

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    Science Advisor

    So given that the luminosities can be added, if the luminosity of each start is L, what is the luminosity of the system? Then, using your first equation, knowing the apparent magnitude of the system, what is the apparent magnitude of each star?
     
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