Scientists Discover Most Energetic Explosions Since the Big Bang: A New Window into Black Hole Secrets
A team of astronomers from the University of Hawaii’s Institute for Astronomy (IfA) has identified a new class of cosmic explosion – extreme nuclear transients (ENTs) – representing the most energetic events observed since the universe’s earliest moments. These cataclysmic occurrences are triggered when massive stars, several times the size of our Sun, are violently torn apart by the immense gravitational forces of supermassive black holes.
These newly discovered events dwarf even supernovae, the already spectacular deaths of massive stars, in terms of energy output. Researchers believe ENTs offer a unique opportunity to study black hole growth and the evolution of galaxies in the distant universe.
Unprecedented Energy Release
One ENT observed by the IfA team released over 25 times more energy than the most powerful supernovae previously known, radiating the equivalent energy of approximately 100 Suns over a single year. “We’ve observed stars getting ripped apart as tidal disruption events for over a decade, but these ENTs are different beasts, reaching brightnesses nearly 10 times more than what we typically see,” explained a researcher at IfA who led the study.
The sheer magnitude of energy released by ENTs allows them to be detected across vast cosmic distances. The initial discovery stemmed from a search for long-lived flares emanating from the centers of galaxies. Further investigation of data from the European Space Agency’s Gaia mission revealed two particularly unusual events – characterized by a prolonged brightening and lacking the typical features of known transients.
Beyond Supernovae: The Role of Supermassive Black Holes
Researchers quickly determined that these events could not be explained by conventional supernovae due to their significantly higher energy output. Instead, the unique characteristics of ENTs strongly suggest the involvement of supermassive black holes. A Hubble Space Telescope image of a galaxy 600 million light-years away showcases a telltale signature of a roaming supermassive black hole actively consuming a star, resulting in a flash of radiation – a tidal disruption event.
“ENTs provide a valuable new tool for studying massive black holes in distant galaxies,” stated Benjamin Shappee, associate professor at IfA and a co-author of the study. “By observing these prolonged flares, we gain insights into black hole growth when the Universe was half its current age, when galaxies were happening places – forming stars and feeding their supermassive black holes 10 times more vigorously than they do today.”
A Rare Phenomenon and the Future of Discovery
ENTs are exceptionally rare, occurring approximately 10 million times less frequently than supernovae, making their detection a significant challenge. However, the next generation of astronomical observatories promises to dramatically increase the rate of discovery. The upcoming Vera C. Rubin Observatory, slated to begin operations in summer 2025, is poised to revolutionize the field.
The Rubin Observatory, equipped with a mirror comparable in size to the largest telescopes on Earth and the world’s largest camera, will scan the entire sky every three nights. It is expected to generate 30 terabytes of data nightly and issue roughly 10 million alerts, fundamentally changing how astronomical research is conducted. A view of the Virgo cluster captured by the Rubin Observatory highlights its ability to observe vast regions of the cosmos.
To follow up on discoveries like these, a telescope capable of monitoring the whole sky is essential. The Rubin Observatory will be instrumental in identifying these “weird” events in the Universe. We are on the cusp of uncovering more ENTs – and countless other novel astronomical phenomena.
This article appeared in the August 2025 issue of BBC Sky at Night Magazine.
