Nightside equilibrium temperature (source code)

= Nightside equilibrium temperature
{title2=$T_n$}

If a fraction $\epsilon$ of total absorbed stellar power reaches the night side, blackbody balance gives
$$
T_n=T_*\sqrt{\frac{R_*}{a}}
\left[\frac{\epsilon(1-A_B)}2\right]^{1/4}.
$$