Using the European Southern Observatory’s (ESO) Very Large Telescope (VLT), astronomers have determined the properties of the bright quasar, revealing that it is not only the brightest object of its kind, but also the brightest object ever observed. Quasars are the bright cores of distant galaxies, fueled by supermassive black holes.

The black hole in this record-breaking quasar is growing by a mass equivalent to one sun per day, making it the fastest black hole ever.

The black holes that power quasars accrete matter around them through an energetic process that emits enormous amounts of light. So much so that quasars are among the brightest objects in our sky, meaning even objects very far from Earth can be seen. Generally, the brightest quasars represent the fastest growing supermassive black holes.

“We have discovered the fastest growing black hole known to date. It has a mass of 17 billion suns and eats up slightly more suns per day. This makes it the brightest object in the known universe,” says astronomer Christian Wolff. at the Australian National University (ANU) and lead author of the published study. Nature Astronomy. The quasar, called J0529-4351, is so far from Earth that its light took more than 12 billion years to reach us.

This video takes us on a journey across the sky from the Milky Way to quasar J0529-4351, the bright core of a distant galaxy in the constellation Painter. Image source: ESO/N. Risinger (skysurvey.org)/Digitized Sky Survey 2/Dark Energy Survey/M. Kornmesser. Music: Astral Electronic

The matter drawn into this disk-shaped black hole emits so much energy that J0529-4351 is 500 trillion times brighter than the Sun. ANU Ph.D. “All of this light comes from a hot accretion disk seven light-years across, possibly the largest accretion disk in the universe,” he says. Student and co-author Samuel Lai. Seven light-years is approximately 15,000 times the distance from the Sun to the orbit of Neptune.

It is noteworthy that this record quasar is hiding in plain sight. “Unexpectedly, it wasn’t until now that we knew of a million less spectacular quasars. It was staring us right in the face until now,” said co-author Christopher Onken, an astronomer at ANU. He added that the object was visible as early as 1980 in images taken by ESO’s Schmidt Southern Sky Survey, but was not recognized as a quasar until decades later.

The search for quasars requires accurate observation data over large areas of the sky. The resulting data sets are so large that researchers often use machine learning models to analyze them and distinguish quasars from other celestial objects.

But these models are trained on existing data, which limits potential candidates to objects similar to those already known. If the new quasar is brighter than any previously observed, the program may reject it and classify it as a star not too far from Earth.

Automated analysis of data from the European Space Agency’s Gaia satellite revealed that J0529-4351 is too bright to be a quasar; This suggests that he is a star. Last year, researchers identified it as a distant quasar using observations from the 2.3-meter ANU telescope at Siding Spring Observatory in Australia.

But finding that this was the brightest quasar ever observed required measurements with a larger telescope and more sensitive instrument. ESO’s X-shooter spectrograph on the VLT in Chile’s Atacama Desert provided important data.

The fastest growing black hole ever observed would also be an ideal target for the GRAVITY+ upgrade to ESO’s VLT Interferometer (VLTI), which is designed to accurately measure the mass of black holes, including those far from Earth. In addition, ESO’s 39-metre Extremely Large Telescope (ELT), under construction in Chile’s Atacama Desert, will further enable the identification and characterization of such elusive objects.

Finding and studying distant supermassive black holes could shed light on some of the mysteries of the early universe, including how they and the galaxies that host them formed and evolved. But that’s not the only reason Kurt is looking for them. “Personally, I love the chase,” he says. “For a few minutes a day, I feel like a kid playing treasure hunt again, and now I bring everything I’ve learned since then to the table.”