Luminosity Calculator

Calculate Stellar Luminosity

Calculate the luminosity of stars using the Stefan-Boltzmann law: L = 4πR²σT⁴.

Star Parameters

R☉

In solar radii (R☉)

K

Surface temperature in Kelvin

Stefan-Boltzmann Law

L = 4πR²σT⁴

where: σ = 5.670×10⁻⁸ W⋅m⁻²⋅K⁻⁴

Note

Luminosity depends on both the star's radius and temperature. Temperature has a stronger effect (T⁴).

Star Comparison

Sun:1 L☉
Sirius:25.4 L☉
Vega:40.1 L☉
Arcturus:170 L☉
Rigel:120,000 L☉
Betelgeuse:126,000 L☉

About Luminosity

Luminosity is the total amount of energy emitted by a star per unit time. It depends on both the star's radius and surface temperature.

  • Proportional to R²
  • Proportional to T⁴
  • Measured in solar luminosities (L☉)

Applications

  • Stellar classification
  • Distance measurements (standard candles)
  • Hertzsprung-Russell diagrams
  • Stellar evolution studies
  • Exoplanet habitability zones