Astronomers discover a new class of cosmic explosion brighter than 100 billion suns

Astronomers have discovered a mysterious new type of cosmic explosion that dwarfs nearly all supernovae ever detected. Within 10 days, the peculiar explosion grew brighter than 100 billion suns and then faded to almost nothing a few weeks later—a destructive event both shorter and more spectacular than a typical supernova.

The fast and furious event likely represents a new class of explosion never before studied, according to research published September 1 in The Astrophysical Journal Letters.

“We have named this new class of sources ‘Luminous Quick Coolers’ or LFC,” the study’s lead author. Matt Nicoll, an astrophysicist at Queen’s University Belfast said in a statement. “The exquisite data set we have obtained rules out that it is another supernova.”

“Our data showed that this event occurred in a massive red galaxy two billion light years away,” study co-author. Shubham Srivastav, a researcher also at Queen’s University, said in the statement. “These galaxies contain billions of stars like our Sun, but they should not have stars large enough to end up as a supernova.”

In addition to its unusual location, the new explosion also became much brighter and faded much faster than a typical supernova, according to the researchers. Over the next 15 days, the object had faded by two orders of magnitude and had faded to just 1% of its maximum brightness just a month after detonating.

Simply put, the explosion did not fit the profile of any known supernova. So, had something like this happened before? To find out, the researchers combed through archival telescope studies, looking for objects with similar brightness and lifetimes. They eventually discovered two other objects, one from a 2009 study and the second from 2020, with similar properties to the newly detected explosion.

The team concluded that these explosions represent a new (and very rare) kind of cosmic explosion that probably has nothing to do with dying stars. So what exactly are LFCs? For now, the team can only speculate.

“The most plausible explanation seems to be a black hole colliding with a star,” Nicholl said.

However, even this explanation does not quite fit; When black holes rip material from passing stars in horrible interactions known as tidal disruption events, they release bright X-ray emissions, and none of the LFCs identified here showed any X-ray emissions.

It could be that scientific models of star-black hole collisions need to be refined, or that astronomers simply don’t have enough information about LFCs to draw conclusions yet. The team will continue to look for more of these mysterious explosions in galaxies closer to Earth.

Source: The Astrophysical Journal Letters, 7658: