An Etymological Dictionary of Astronomy and Astrophysics

The total amount of energy emitted by a star per unit time. According to the → Stefan-Boltzmann law, the stellar luminosity is given by: L = 4πR²σT_eff⁴, where R_* is radius, σ is the → Stefan-Boltzmann constant, and T_eff is → effective temperature. A star’s luminosity depends, therefore, on two factors, its size and its surface temperature. Stellar luminosity is measured either in ergs per second or in units of → solar luminosity or in → absolute magnitude. See also → luminosity class.

See also: → stellar; → luminosity.