A foe is a unit of energy equal to 1044 joules or 1051 ergs, used to measure the large amount of energy released by a supernova.

The word is an acronym derived from the phrase [ten to the power of] fifty-one ergs.

This unit of measure is convenient because a supernova typically releases about one foe of observable energy in a very short period (which can be measured in seconds). In comparison, if the Sun had its current luminosity throughout its entire lifetime, it would release 3.827×1026 W (Symbol for Watt) × 3.1536×107 s/yr × 1010 yr ≈ 1.2 foe.




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Observable Universe