Surface brightness to luminosity

by Warimi
Tags: brightness, luminosity, surface
Warimi is offline
Dec8-12, 06:39 PM
P: 1
Can anyone offer insight into the derivation of the surface brightness to solar luminosity conversion

S(mag/arcsec^2) = Mabs + 21.572 - 2.5log S (Solar luminosities/pc^2)

More or less my concern is the constant term, is it empirically observed value or is there a derivation for it?

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Dec9-12, 09:45 AM
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The definition of magnitude and parsec are arbitrary, and if you take the log of those (multiplicative) constants and add everything you should get 21.572 in some way.

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