A hugely bright object, known as a quasar, has been confirmed to be not just the most luminous known example of its kind, but also the brightest object ever seen.
A quasar forms when the accretion disc of gas and dust around a supermassive black hole at the heart of a galaxy becomes so hot it begins to glow brightly.
To us here on Earth, the result closely resemble a star.
This particular quasar, J0529-4351 has actually been seen in images as far back as 1980 but was mistakenly identified for decades.
“It is a surprise that it has remained unknown until today, when we already know about a million less impressive quasars. It has literally been staring us in the face until now,” says Christopher Onken from Australia National University who took part in the study.
The brightest quasar ever spotted
The record-breaking galaxy weighs in at 17 billion solar masses. It devours a Sun’s worth of material every day, making it the fastest growing black hole to date as well as the brightest object ever seen.
It is so far away it has taken its light 12 billion years to reach us.
This cosmic feast causes its accretion disc to glow so brightly its over 500 trillion times more luminous than the Sun.
“All this light comes from a hot accretion disc that measures seven light-years in diameter — this must be the largest accretion disc in the Universe," says Samuel Lai, also from ANU.
The object is so bright that many automated searches, which use previous observations as a baseline, passed it over as being too bright to be a quasar.
It was only when it was re-examined with the 2.3m telescope at Siding Spring Observatory in Australia that its true nature became clear.
Quasars such as J0529-4351 are bright enough that we can see them across enormous distances, giving us a window back into the earliest times of the Universe.
They also allow us to study the usually invisible supermassive black holes in the hearts of galaxies, which in turn gives us insight into how galaxies form and evolve.
“Personally, I simply like the chase,” says Christian Wolf from Australian National University (ANU) who led the study. “For a few minutes a day, I get to feel like a child again, playing treasure hunt, and now I bring everything to the table that I have learned since.”
