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I Cgs to SI unit conversion

  1. Jun 21, 2016 #1

    I have a value that is 10.7 mJy, that I need to convert to SI units. I thought it would be 1.7*10^(-2)*10^(-26) but that might be wrong?

    Then I have a flux value, kappa, of 2 cm^2.g^(-1) that needs to be converted to meters and kilogram. I thought it was 2*10^(-7) m2/kg, but that might be wrong as well. I would get the 10^(-4) from converting from cm2 to m2 and the 10^(-3) from converting from g to kg.

    Can anyone help?
  2. jcsd
  3. Jun 21, 2016 #2


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    In the second part, you have the grams conversion wrong because it has a negative exponent. You should be dividing by 10^(-3), not multiplying by it.

    I have no idea what a mJy is, but the 10^(-26) is a truly large factor.
  4. Jun 21, 2016 #3


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    10.7 = 1.07 × 10

    10.7 m = 10.7 × 10-3 = 1.07 × 10-2

    Don't drop those zeroes!

    BTW, this is the definition of the Jansky (Jy):


    1 Jy = 10-26 W / (m2-Hz)
  5. Jun 21, 2016 #4
    Thank you!
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