Visual band luminosity?

Question

I know that the sun has an absolute visual magnitude of 4.8. I also know that it has a total luminosity of 3.84 x 10^26 W.

I also know that its luminosity in the visual band is 4.44 x 10^25 W. Can someone explain how this figure is derived from the total luminosity and magnitude? What equations do I need?

Answer 1

Hi. The absolute magnitude is just a measure of visual magnitude at a common distance. Visual magnitude is a human measure, since we see some colors better than others. (Evolution around a type G3 star.) Some stars are much brighter in blue light, some in infrared, some in X-rays. Do not know the formulas, sorry, but any star's absolute magnitude gives a common starting point.