这颗恒星的亮度是太阳的50倍。

The ___luminosity of this star is 50 times that of the sun.

科学家通过测量恒星的亮度来研究其能量输出。

Scientists study the energy output of stars by measuring their ___luminosity.

他演讲的光彩给观众留下了深刻印象。

The ___luminosity of his speech left a deep impression on the audience.