luminosity

1. (uncountable) the state of being luminous, or a luminous object; brilliance or radianceuncountable

2. (physics) the ratio of luminous flux to radiant flux at the same wavelength; the luminosity factorcountableuncountable

3. (astronomy) The rate at which a star radiates energy in all directions.Examples: "We recognize the same pattern as in the left panel, with dM stars being much less frequent flarers than dMe stars of similar luminosity."; "We derive rotation periods, photometric activity indices, flaring energies, mass loss rates, gyrochronological ages, X-ray luminosities and consider implications for the planetary magnetospheres and habitability."countableuncountable