Which characteristic is used to measure the amount of light radiated by a star?

Luminosity is the characteristic which is used to measure the amount of light radiated by star.

Explanation:

A star which emits light throughout universe is massive ball of plasma.In our solar system we have only one star that is sun but in the universe there are stars which are countless.

The mass,surface temperature, size, color and brightness are the characters with which the stars are defined.

The magnitude and luminosity are the two characters by which brightness of star is defined.

The amount of light that is radiated by star is called as luminosity and the surface temperature and size determines the luminosity.

Luminosity is the total energy produced  by the star in one second from its surface.

it takes about 30 days for it to break down

increase masses, decrease separation