# Absolute Magnitude of Lightbulb

by tomeatworld
Tags: absolute, lightbulb, magnitude
 P: 51 1. The problem statement, all variables and given/known data By comparing with the luminosity of the Sun, calculate the absolute magnitude of a 60W lightbulb. [THe absolute magnitude of the Sun is +4.75; you may ignore colour differences] 2. Relevant equations m-M=5log(d/10pc) $$f = \frac{L}{4\pi d^{2}}$$ m1 - m2 = -2.5long(f1 / f2) 3. The attempt at a solution I'm not really sure where to start. I know the luminsoty of the Sun to be 3.8x1026W but I'm not sure how it helps.