Astronomers measure total starlight emitted over 13.7bn years

Stars have radiated 4x10⁸⁴ photons since the universe begun with formation peaking 11bn years ago

All the light from all the stars that have ever existed. It is a quantity of unimaginable magnitude, but now astronomers have put a number on it.

From the earliest, faintest stars, to the largest galaxies, an international team has managed to measure the total amount of starlight emitted over the entire 13.7bn-year history of the universe.