Astronomers have made an astounding discovery of the brightest flare ever observed from a supermassive black hole. This flare was so intense that it can only be attributed to a tidal disruption event (TDE), where a colossal star was torn apart by a distant galaxy’s black hole, unleashing an extraordinary burst of energy that is still resonating.

Originating from an active galactic nucleus (AGN) — a supermassive black hole at the core of a galaxy consuming matter — this event is approximately 20 billion light-years from Earth, marking it as one of the most distant TDEs recorded. Notably, many TDEs remain undetected in AGNs due to the fluctuating brightness near these active black holes, which obscures the distinction between a TDE and other phenomena.

“For the last 60 years, we have understood AGNs to be highly volatile, but we lacked clarity about their variability,” explains Matthew Graham from the California Institute of Technology. “Currently, we are aware of millions of AGNs, yet their variability remains largely a mystery.” The event, dubbed “Superman” due to its remarkable brightness, holds the potential to unravel some of these cosmic enigmas.

Initially identified in 2018, astronomers speculated that Superman might merely be a bright explosion from a relatively nearby galaxy. It wasn’t until 2023 that subsequent observations unveiled its true distance and revealed that its brightness was significantly more intense than initially estimated.

This first flare enhanced AGN visibility to over 40 times greater and was 30 times more powerful than any other flare recorded from AGN. Graham and his research team concluded that the most plausible explanation is the disintegration of a massive star, possibly over 30 times the mass of the Sun.

All active supermassive black holes are surrounded by a region of infalling material known as an accretion disk. The matter density in this area is expected to yield substantial stars, although they have never been directly observed. “If our interpretation of this as a TDE is correct, it substantiates our hypothesis regarding the existence of these massive stars in such environments,” noted Graham.

“We once believed that active supermassive black holes simply housed gas disks that meandered about. However, this scenario is much more dynamic and active,” he adds. By examining the fading Superman, we may uncover a deeper understanding of its environment.

Moreover, it may lead to the establishment of a model for TDEs in AGNs, enhancing future detection efforts. “When a potential TDE is identified in an AGN, it remains uncertain whether it is merely an active galactic nucleus or if a true TDE is occurring, so having such unambiguous evidence is invaluable,” states Vivian Baldassare from Washington State University. “This will greatly aid in revealing future TDEs and understanding various AGN variability sources.”