Luminosity



In astronomy, luminosity is the total amount of energy emitted by a star, galaxy, or other astronomical object per unit time. It is related to brightness, which is the luminosity of an object in a given spectral region.

Luminosity is measured in joules per second or watts. Values for luminosity are often given in terms of the luminosity of Sol, which has a total power output of 3.846×1026 W. The symbol for solar luminosity is L⊙. Luminosity can also be given in terms of magnitude. The absolute bolometric magnitude (Mbol) of an object is a logarithmic measure of its total energy emission.