This quantity was erroneously observed to increase with distance under a form of selection bias discovered by Gunnar Malmquist. The number density of galaxies is given as a function of this quantity in an equation named for Schechter. This quantity is approximately proportional to the fourth power of stellar velocity dispersion (20[1])according to the (*) Faber–Jackson relation. Adapting the Stefan–Boltzmann law to stars replaces radiant emittance with this (10[1])quantity. Henrietta Swan Leavitt discovered a relationship between this quantity and period for Cepheid variables. An observer-dependent measure of this quantity is apparent magnitude. For 10 points, name this intrinsic measure of the amount of light radiated by an object. ■END■