Online luminosity calculator to calculate total amount of energy emitted as a black body radiation by a star, galaxy, or other astronomical object per unit time.
Formula:
L = σ • A • T4
where,σ = Stefan–Boltzmann constant [5.670373x10-8W⋅m−2⋅K−4],
A = area of the illuminated surface,
T = temperature (in Kelvins),
L = luminosity