Luminosity
In physics, luminosity is the density of luminous intensity in a given direction.
In
astronomy,
luminosity is the amount of
energy a body radiates in unit
time.
Stellar luminosities are usually expressed as
solar luminosities,
L; that is, how many times more energy the object radiates in comparison to the
Sun. In
X-ray and
radio wavelengths, luminosity is sometimes expressed in
watts. Stars with
bolometric magnitudess of -10 have luminosities of 10
6L and stars with bolometric magnitude of +17 have luminosities of 10
-5L. The
Hertzsprung-Russell diagram relates luminosity with
absolute magnitude,
stellar classification, and surface
temperature.