A collaboration between earth based and space telescopes have created an entire sky map of all light from all observable stars in the universe … and it does not look like the Eye of Sauron.
Well, perhaps just a little.
From their laboratories on a rocky planet dwarfed by the vastness of space, scientists have collaborated to measure all of the starlight ever produced throughout the history of the observable universe.
… This map of the entire sky shows the location of 739 blazars used in the Fermi Gamma-ray Space Telescope’s measurement of the extragalactic background light (EBL). The background shows the sky as it appears in gamma rays with energies above 10 billion electron volts, constructed from nine years of observations by Fermi’s Large Area Telescope. The plane of our Milky Way galaxy runs along the middle of the plot. …
Astrophysicists believe that our universe, which is about 13.7 billion years old, began forming the first stars when it was a few hundred million years old. Since then, the universe has become a star-making tour de force. There are now about two trillion galaxies and a trillion-trillion stars. Using new methods of starlight measurement, Clemson College of Science astrophysicist Marco Ajello and his team analyzed data from NASA’s Fermi Gamma-ray Space Telescope to determine the history of star formation over most of the universe’s lifetime.
A collaborative paper titled “A gamma-ray determination of the Universe’s star-formation history” was published Nov. 30 in the journal Science and describes the results and ramifications of the team’s new measurement process.
“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,” said Ajello, who is lead author of the paper. “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.”
Putting a number on the amount of starlight ever produced has several variables that make it difficult to quantify in simple terms. But according to the new measurement, the number of photons (particles of visible light) that escaped into space after being emitted by stars translates to 4×10^84. …
Despite this stupendously large number, it is interesting to note that with the exception of the light that comes from our own sun and galaxy, the rest of the starlight that reaches Earth is exceedingly dim — equivalent to a 60-watt light bulb viewed in complete darkness from about 2.5 miles away. This is because the universe is almost incomprehensibly huge. This is also why the sky is dark at night, other than light from the moon, visible stars and the faint glow of the Milky Way. …
What do you see in the map of all starlight? To me it looks a bit like the remnants of a big explosion, something that would have made quite a bang… but I sometimes have an overactive imagination. 😉