= Equilibrium temperature of a circumbinary planet
{title2=$T_{\rm eq}$}
For <blackbody> stars of radii $R_A,R_B$ and <temperatures> $T_A,T_B$, a distant <circumbinary planet> with <Bond albedo> $A_B$ and uniform global reradiation has <planetary equilibrium temperature>
$$
T_{\rm eq}^4=\frac{1-A_B}{4a^2}(R_A^2T_A^4+R_B^2T_B^4).
$$
This neglects internal cooling, eccentricity, and corrections from finite binary separation. The stars heat the planet through the sum of their absorbed bolometric fluxes, not an average of their <temperatures>.
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