Copyright Interesting Engineering
Researchers have discovered the brightest and most powerful flare ever seen from a supermassive black hole. Located about 10 billion light-years away, this black hole, called “J2245+3743,” is estimated to have a mass of around 500 million Suns. Around 2018, it suddenly brightened 40-fold and became 30 times brighter than any similar event ever observed. At its peak, the researchers explain, it shone with the power of 10 trillion Suns. According to the team, this flare came from something called a “Tidal Disruption Event” (TDE). This occurs when a star wanders too close to a black hole and gets torn apart by its immense gravity. The physics is complex, but you can imagine it like the star being stretched and shredded into a stream of gas. Part of that gas gets slingshotted away, while the rest spirals into the black hole, heating up and glowing extremely bright. Big boom in the darkness of space It is this that results in the flares that astronomers are able to detect. In this case, the doomed star must have been massive (about 30 times the Sun’s mass), which made the flare exceptionally powerful. According to the team, the total energy released was about 10⁵⁴ ergs. An erg is a unit of energy equal to 10−7 joules (100 nJ). The amount produced by this observed event is, therefore, equivalent to turning the entire mass of the Sun into pure energy (E = mc²). To put that into perspective, that’s millions of times more energy than a typical supernova. This event stands out for several reasons, such as its exceptional brightness. Nothing like it has been seen before. Another standout feature is its distance and age. The light traveled 10 billion years to reach us, so this must have happened when the universe was only about one-third of its current age. The location or environment is also interesting. It occurred inside an Active Galactic Nucleus (AGN), or a galaxy core already glowing because its central black hole is feeding on gas. “Stars this massive are rare,” explained astronomer K. E. Saavik Ford of City University of New York, “but we think stars within the disk of an AGN can grow larger. The matter from the disk is dumped onto stars, causing them to grow in mass.” “The energetics show this object is very far away and very bright,” astrophysicist Matthew Graham of Caltech explained. “This is unlike any AGN we’ve ever seen,” he added. A rare cosmological delight TDEs are rarely detected in AGNs because their brightness usually hides such flares. The duration is also of note, with the team noting that it has been slowly fading for over six Earth-years. But due to cosmological time dilation (space expansion stretching time), it probably lasted only about two years where it happened. This discovery sets a new record for the most luminous black-hole-related flare ever recorded. It also demonstrates that very massive stars can exist within the dense gas disks of AGNs and that such stars can be torn apart in rare, spectacular events. It also helps scientists refine models of black-hole feeding and time dilation effects in distant galaxies. The study also shows the value of long-term sky surveys like the Zwicky Transient Facility (ZTF) and Catalina Real-Time Transient Survey, which continuously monitor changes in the night sky. You can view the study for yourself in the journal Nature Astronomy.
