Free Eddington Luminosity Calculator

Compute the Eddington luminosity, the maximum luminosity a body can achieve when radiation pressure balances gravity: L_Edd = 4 pi G M c / kappa.

kg

Eddington Luminosity

14,708,643,955,456,562,000,000,000,000,000.000 W

In Solar Luminosities38,423.83 L_sun

Eddington Luminosity vs Object Mass

The Eddington Luminosity

The maximum luminosity where radiation pressure on infalling matter balances gravitational attraction.

Formula

L_Edd = 4π G M c / κ

Using electron-scattering opacity κ ≈ 0.034 m²/kg for ionised hydrogen. For a solar-mass object, L_Edd ≈ 3.3 × 10⁴ L_sun.

Exceeding L_Edd causes radiation-driven mass loss (stellar winds, super-Eddington outbursts).

Example Calculation

A 1-solar-mass object.

  1. 01L_Edd = 4π G M c / κ
  2. 02= 4π × 6.674e-11 × 1.989e30 × 2.998e8 / 0.034
  3. 03Numerator = 4π × 3.979e28 = 4.988e29
  4. 04L_Edd = 4.988e29 / 0.034 ≈ 1.47e31 W ≈ 38 300 L_sun

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