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Calculating absolute magnitude and apparent magnitude

  1. Feb 14, 2009 #1
    Ummm... never mind, we found it...

    1. The problem statement, all variables and given/known data

    Given Proxima Centauri with parallax angle of 0.769" and apparent bolometric magnitude of 11.1... what is its absolute magnitude?

    2. Relevant equations

    I get that I should use m-M = 5 log10(d/10 pc) and I understand that d = 1/p".

    What I really need to know is: what do I use to get apparent magnitude? After I get m I can plug and chug, and I'm fine with that... but how do I get m?

    Apparent magnitude was not given and I can't look it up for a quiz or test.

    3. The attempt at a solution

    so far...

    m-M = 5 log10 [(1/0.769)/10]

    or M = m - 5 log10 (.1300)

    But I'm still stuck on where to go for m...


    Lori the Totally Lost English Major
    Last edited: Feb 14, 2009
  2. jcsd
  3. Feb 14, 2009 #2


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    Science Advisor
    Homework Helper

    They gave you the "apparent bolometric magnitude", just use that. The only difference between that and "apparent visual magnitude" is what wavelengths of light are being measured.
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