A cosmic explosion with an energy equivalent to the output of a billion suns went unnoticed by astronomers until they caught the "echo" of this gamma-ray burst.

Astronomers missed a space explosion as powerful as a billion suns — until they spotted its echo

Source: space
Source Link: https://www.space.com/astronomy/astronomers-missed-a-space-explosion-as-powerful-as-a-billion-suns-until-they-spotted-its-echo