Free Astronomy Magazine May-June 2024

13 MAY-JUNE 2024 ASTRO PUBLISHING minous object in the known Uni- verse,” says Christian Wolf, an as- tronomer at the Australian National University (ANU) and lead author of the study published in Nature As- tronomy . The quasar, called J0529- 4351, is so far away from Earth that its light took over 12 billion years to reach us. The matter being pulled in toward this black hole, in the form of a disc, emits so much energy that J0529- 4351 is 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 Uni- verse,” says ANU PhD student and co-author Samuel Lai. Seven light- years is about 15,000 times the dis- tance from the Sun to the orbit of Neptune. And, remarkably, this record-breaking quasar was hiding in plain sight. “It is a surprise that it has remained unknown until today, when we already know about a mil- lion less impressive quasars. It has literally been staring us in the face until now,” says co-author Christo- T his artist’s impression shows the record-breaking quasar J059-4351, the bright core of a distant galaxy that is powered by a supermassive black hole. Using ESO’s Very Large Telescope (VLT) in Chile, this quasar has been found to be the most luminous object known in the Universe to date. The supermassive black hole, seen here pulling in surrounding matter, has a mass 17 billion times that of the Sun and is growing in mass by the equivalent of another Sun per day, making it the fastest-growing black hole ever known. [ESO/M. Kornmesser]