Energy Balance
 Coupling between thermal conduction and radiative transfer
kT=kf+kes
kf, kp, kj = flux, planck and absorption mean opacities
kes = 0.2(1+X) = scattering opacity
X = hydrogen fraction
Thermal conductivity
Boundary conditions:
Energy-averaged and angle-averaged depression factor for the surface emissivity (computed numerically as before)