Luminosity of a spherical blackbody
= Luminosity of a spherical blackbody
An isotropic blackbody surface has outward flux $F=\pi\int B_\nu\,d\nu=\sigma T^4$. A sphere of radius $R$ therefore has luminosity
$$
L=4\pi R^2\sigma T^4.
$$
= Luminosity of a spherical blackbody
An isotropic blackbody surface has outward flux $F=\pi\int B_\nu\,d\nu=\sigma T^4$. A sphere of radius $R$ therefore has luminosity
$$
L=4\pi R^2\sigma T^4.
$$