Scientists Measure All Starlight Ever Produced By The Universe

Star gazer SWNS

As Christmas draws nearer and tales of wise men following stars to find baby kings are rife, scientists have revealed their own findings on interstellar goings on.

Researchers have kept themselves busy measuring all the starlight ever produced by the observable universe for the first time.

It comes to 4*10^84 photons – yeah me either, but there is a simpler explanation.

The figure means the number four followed by 84 zeros, according to data from NASA’s Fermi Gamma-ray Space Telescope low-orbit space observatory.

Orion's swordNASA

Astrophysicists calculated the incomprehensibly large number by analysing nine years worth of rays from 739 blazars, which are galaxies containing super-massive black holes for those not already in the know…

Data allowed researchers to measure the density of ‘cosmic fog’ over almost the entire 13.7 billion year history of the universe, according to Assistant Professor Marco Ajello.

Comparing with background radiation they came up with the amount of light ever created in the trillion trillion stars in the observable universe.

Lead author Dr Ajello, of Clemson University in the US, said:

From data collected by the Fermi telescope, we were able to measure the entire amount of starlight ever emitted. This has never been done before.

Most of this light is emitted by stars that live in galaxies. And so, this has allowed us to better understand the stellar-evolution process and gain captivating insights into how the universe produced its luminous content.


He added:

Gamma-ray photons traveling through a fog of starlight have a large probability of being absorbed.

By measuring how many photons have been absorbed, we were able to measure how thick the fog was and also measure, as a function of time, how much light there was in the entire range of wavelengths.

The findings are due to be published in the journal Science, should you require a little more detail.

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