The brightest objects are sometimes the ones that are the most difficult to find – that's why it took so long for astronomers to discover the brightest quasar of the last 9 billion years. Powering this extreme object is a supermassive black hole hundreds of times bigger than the one at the center of the Milky Way. It is the fastest-growing supermassive black hole ever found.
The quasar's true luminosity is equivalent to about 7,000 times the entire Milky Way's combined luminosity Way. It is so bright that it reaches a magnitude of 14.5 – bright enough to be visible with a standard personal telescope, so you could easily see the brilliant effects of this feeding black hole by yourself.
“Astronomers have been hunting for objects like this for more than 50 years. They have found thousands of fainter ones, but this astonishingly bright one had slipped through unnoticed,” lead author Dr Christopher Onken, from Australia National University, said in a statement.
The work is available on the ArXiv and submitted to Publications of the Astronomical Society of Australia. It is puzzling that an object like this is still accreting mass – most supermassive black holes from the time of this one had already settled down.
This object (known as SMSS J114447.77-430859.3) continues to feed undeterred. The quasar could be the result of a galaxy merger that provided the supermassive black hole with a gas reservoir big enough to feed it for billions of years, making it so bright.
“This black hole is such an outlier that while you should never say never, I don't believe we will find another one like this,” co-author Associate Professor Christian Wolf added. “We are fairly confident this record will not be broken. We have essentially run out of sky where objects like this could be hiding.”
The supermassive black hole weighs around 3 billion times the mass of the Sun, quite the sizable object. Its light comes to us from when the Universe was about half of its current age.
“It is 500 times bigger than the black hole in our own Galaxy,” explained co-author and ANUgraduate researcher Samuel Lai. “The orbits of the planets in our Solar System would all fit inside its event horizon - the black hole's boundary from which nothing can escape.”