Exoplanet Temperature Calculator

All physics tools

Estimate the equilibrium temperature of a planet outside our solar system.

Star & Orbital Properties

Star Temperature (K)

Star Radius (Solar Radii)

Orbital Distance (AU)

Bond Albedo (0-1)

Temperature Results

Enter star and planet data

About this calculator

Quick Reference

T*Star effective temperature

R*Star radius

aSemi-major axis

ABond albedo

Overview

Equilibrium temperature is the theoretical temperature a planet would reach if it were a blackbody heated only by its parent star, without considering the greenhouse effect.

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Pro Tips

Formula: Teq = Tstar * sqrt(Rstar / 2a) * (1-A)^(1/4).
Albedo (A) is the fraction of light reflected back into space (Earth is approx 0.3).
AU is the distance from Earth to the Sun (approx 150 million km).

Fun Facts

"The 'Habitable Zone' is the region around a star where liquid water could exist on a planet's surface."
"Venus has a high albedo but is very hot due to a runaway greenhouse effect."
"The first exoplanet around a sun-like star, 51 Pegasi b, was discovered in 1995."

Formula: Teq = T*[R*/2a]^{1/2}(1-A)^{1/4}