intrinsic brightness
Noun
Meaning
intrinsic brightness (plural intrinsic brightnesses)
English Wikipedia has an article on:intrinsic brightnessWikipedia
The brightness a star would have if not attenuated by distance or intervening gas or dust. As opposed to apparent brightness which it has as measured at a distance.
Examples
The intrinsic brightness of theSun is fully 5,000 times as great as if the whole surface were formed of the molten steel just issuing from the Bessemer converter.