Effective Planet Temperature

Teff=((L☉ (1-A))/(16πσa^2 ))^(1/4)

Teff is the effective surface temperature not accounting for greenhouse effect (kelvin)

L☉ is the luminosity in solar units and must be converted to watts L☉∙3.846×10^26 W

A is the geometric albedo (earth = 0.367)

σ is the Stefan-Boltzmann constant 5.670400×10^(-8) J s^(-1) m^(-2) K^(-4)

a is the semi-major axis(meters)

To get minimum Teff and maximum Teff adjust to perihelion and apohelion

This does not take into account any greenhouse effect factor,H,to add in H use the following

modification to the T_eff formula

Twgh=Teff(1+0.15∙H/|H|∙|H|^(1/2))

Twgh is the temperature factoring in with the greenhouse effect

H is the Green House Factor (earth = 1).

It is not unusual for H to be a negative value for bodies who either have

a highly reflective surface or a thin conductive atmosphere, Enceladus and Mars

are prime examples.

For gas planets that are in excess of 12 Mjup black body value for

planet should be included at equatorial radius as planet will most

likely still be radiating heat from formation.