NASA Spots Black Holes Eating Stars To Create Biggest Boom Since Big Bang
by Aaron Leong · HotHardwareScientists have identified a new class of cosmic explosions, dubbed "extreme nuclear transients" (ENTs), that represent the most energetic events observed in the universe, perhaps since the Big Bang itself. These massive energy outbursts are the result of supermassive black holes feasting on colossal stars, creating a spectacle of light and energy that dwarfs even the most powerful supernovae.
A recent study, leveraging data from NASA, the European Space Agency (ESA), and numerous ground-based observatories, details three such occurrences. Each event involved a supermassive black hole, residing at the heart of a distant galaxy, devouring a star between three and ten times the mass of our Sun. Unlike typical black hole feeding events, these ENTs shine with an intensity that can last for several months, emitting more energy than a hundred supernovae combined.
Jason Hinkle, a graduate student at the University of Hawaii and lead author of the study explains that "these events are the only way we can have a spotlight that we can shine on otherwise inactive massive black holes." He notes that the destruction of these massive stars unleashes enormous amounts of high-energy radiation, significantly impacting the central regions of their host galaxies.
The discovery of ENTs began with Hinkle and his team's meticulous search through public transient surveys for long-lived flares emanating from galactic centers. Two particularly anomalous flares captured by ESA's Gaia mission in 2016 and 2018, along with a third detected by the Zwicky Transient Facility in 2020, hinted at something unique. Further analysis, including critical observations from NASA's Neil Gehrels Swift Observatory, confirmed that these events were not stellar explosions but rather the unmistakable sign of black holes ripping stars apart.
The most powerful ENT documented, Gaia18cdj, unleashed an astonishing 25 times more energy than the most energetic known supernovae. To put this into perspective, a standard supernova releases as much energy in a year as our Sun will in its entire 10 billion-year lifespan. ENTs, however, can radiate the energy of 100 Suns in a single year.
Catching one of these rare cosmic events is special enough as well as they occur at least 10 million times less frequently than supernovae.
Photo credits: University of Hawai'i