Astronomy & Space
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Stefan–Boltzmann Law

Luminosity of a star from radius and temperature.

Formula

L=4πR2σT4L = 4\pi R^2 \sigma T^4

Variables

RRadius
\sigmaStefan constant
TSurface temperature

Example

The Sun’s huge luminosity comes from its surface radiating at ~5800 K over a vast area.

Did You Know?

This law lets astronomers gauge a star's size from its temperature and total brightness.

starsluminosityradiation