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?

Phys.Org News Partner Astronomy news on
Astronomers: 'Tilt-a-worlds' could harbor life
Pushy neighbors force stellar twins to diverge
Image: Multiple protostars within IRAS 20324+4057
mfb is online now
Dec9-12, 09:45 AM
P: 10,767
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.

Register to reply

Related Discussions
Computing luminosity from surface brightness Introductory Physics Homework 0
Tolman Surface Brightness Test -- need help! Cosmology 10
Tolman surface brightness test -- need help! Astrophysics 3
Surface brightness Advanced Physics Homework 9
Inverse square law.....intensity-brightness-luminosity-distance General Physics 1