# Tag Info

If you're just looking for an equivalent expression, but relative to the sun, the modification is pretty simple. Let's start with the original expression: $$B=\frac{A \cdot L_S \cdot R^2}{D^2 \cdot d^2}$$ where $B$ = Brightness of observed object in watts $A$ = Albedo of observed object $L_S$ = Luminosity of the Sun in watts $R$ = Radius of the observed ...