flux f ∼ 3 × 10^{−14} \frac{Joule}{m^{2} s}

R = vt = 1.4 × 10^{13} m

L ≃ 4πR^{2} σT^{4}

(m − M) = 5 log(d) − 5

flux f = \frac{L}{4πd^{2}}