What scenario allows a smaller, very hot star to outshine a substantially larger, cooler star?

Answer

The superior temperature compensates for the smaller radiating surface.

Because temperature increases luminosity output per area exponentially (as per the Stefan-Boltzmann relation concept), a high temperature can overcome the luminosity deficit caused by a smaller physical radius.

What scenario allows a smaller, very hot star to outshine a substantially larger, cooler star?

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Why Would The Size Of A Star Affect Its Luminosity? - Physics Frontier

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