luminosity

English

Borrowed from French luminosité or else a native formation from luminous +‎ -ity.^[1]^[2]

luminosity (countable and uncountable, plural luminosities)

(uncountable) the state of being luminous, or a luminous object; brilliance or radiance
- 1994, Simcha Paull Raphael, Jewish Views of the Afterlife, page 360:
  They reported encountering a luminosity of great intensity and loving angelic beings.
(physics) the ratio of luminous flux to radiant flux at the same wavelength; the luminosity factor
(astronomy) The rate at which a star radiates energy in all directions.
- 2012, O. Havnes, B. R. Pettersen, J. H. M. M. Schmitt, Activity in Cool Star Envelopes: Proceedings, page 56:
  We recognize the same pattern as in the left panel, with dM stars being much less frequent flarers than dMe stars of similar luminosity.
- 2015, D. J. Armstrong, C. E. Pugh, A.-M. Broomhall, D. J. A. Brown, M. N. Lund, H. P. Osborn, D. L. Pollacco, “The Host Stars of Keplers Habitable Exoplanets: Superflares, Rotation and Activity”, in arXiv‎^[1]:
  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.

state of being luminous

ratio of luminous to radiant flux

rate at which a star radiates energy