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Early Beacon

May 29, 2015

Barely a billion years after the Big Bang, a brilliant light was already shining across the universe. It was thousands of times brighter than a whole galaxy of stars. Yet it wasn’t much bigger than the modern-day solar system — a tiny but powerful beacon that is still visible today.

That beacon is a quasar. At its center is a black hole about 12 billion times the mass of the Sun. Gas is spiraling into the black hole. As it gets close to the black hole, it moves at a large fraction of the speed of light. The gas is heated to millions of degrees, so it glows brightly. In fact, this is the brightest quasar yet discovered in the early universe.

Even so, it’s not easy to see because it’s almost 13 billion light-years away. At that great distance, it’s not much more than a pinpoint of light in even the largest telescopes. In fact, astronomers only recently discovered it with the help of several giant telescopes.

When we see something that’s that far away, we’re seeing it as it looked in the distant past — in this case, almost 13 billion years ago, when the universe was young.

The universe contained a lot more gas than it does today, so there was more material to fuel quasars. Much of the gas in the galaxies around the quasars soon coalesced to give birth to stars. That deprived the black holes of fuel, so the quasars shut down. The black holes remain, but they are much quieter — lurking at the hearts of ancient galaxies.


Script by Damond Benningfield, Copyright 2015

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