standard candle

美 [ˈstændərd ˈkændl]英 [ˈstændəd ˈkændl]

standard candle

noun

the basic unit of luminous intensity adopted under the Systeme International d'Unites;equal to 1/60 of the luminous intensity per square centimeter of a black body radiating at the temperature of 2,046 degrees Kelvin: Synonym: candle candela cd

数据来源：WordNet

1

Supernovae of Type la ( SNe la ) are becoming more significant objects , which can be used as a standard candle to measure distances to remote galaxies-and hence to determine the expansion rate of the universe .

Ia超新星作为测量遥远星系距离（从而测定宇宙膨胀速率）的标准烛光，已经成为具有重要意义的天体。
2

Since the speed of light is constant , knowing how far away such a " standard candle " is ( calculated from its apparent brightness seen from Earth ) is to know how long ago it exploded .

再加上光速是恒定的，知道这样一盏“标准蜡烛”离地球多远（根据地球上观测的视觉亮度计算得出）就能知道它是多久以前爆发的。