Besides surface temperature, what other measurable property directly influences a star's luminosity?

Answer

Its surface area (radius).

Luminosity is intrinsically tied to temperature and mass. The radius, which determines the surface area available to radiate energy, also plays a role, often expressed through the Stefan-Boltzmann Law.

Besides surface temperature, what other measurable property directly influences a star's luminosity?
temperaturepropertystarmassphysical