Latest news with #InstituteForAstronomy
Yahoo
15 hours ago
- Science
- Yahoo
Astronomers Astonished by Largest Explosion Since the Big Bang
You've heard of how mighty supernovas are, or of the ungodly amounts of energy released by gamma ray bursts. But astronomers have just discovered a type of cosmic blast that puts all those to shame. They're called "extreme nuclear transients" (ENTs) — and they're quite literally the most powerful explosion witnessed since the dawn of time. What produces ENTs is appropriately catastrophic: a star, at least three times as massive as our Sun, being obliterated by a supermassive black hole. "We've observed stars getting ripped apart as tidal disruption events for over a decade, but these ENTs are different beasts, reaching brightnesses nearly ten times greater than what we typically see," Jason Hinkle, lead author of a new study published in the journal Science Advances, and a researcher at the University of Hawai'i's Institute for Astronomy (IfA), said in a statement about the work. "Not only are ENTs far brighter than normal tidal disruption events, but they remain luminous for years, far surpassing the energy output of even the brightest known supernova explosions," Hinkle added. The first clues emerged when Hinkle and his team were trawling through public data collected by the European Space Agency's Gaia mission, a vast three-dimensional map of over two billion stars and counting. Amid this stellar sea, they noticed flares of light, including one recorded in 2016 and another in 2018, that inexplicably lasted for several years. Most cosmic explosions, for comparison, only shine for several weeks. "When I saw these smooth, long-lived flares from the centers of distant galaxies, I knew we were looking at something unusual," Hinkle said. He wasn't the only one on the scent. Back in 2023, another team of astronomers reported a similar detection with the Zwicky Transient Facility in California. Following-up on these findings, Hinkle conducted additional observations with other telescopes, including the Keck Observatory in Hawaii, and linked these phenomena together. The most formidable ENT, assigned the screenname-esque moniker of Gaia18cdj, unleashed 25 times more energy than the most powerful supernova ever detected. In one year, it radiated energy equal to all the energy our Sun will produce in its entire lifetime across billions of years — times one hundred. Typically, a supernova produces "just" one Sun's worth of energy. To produce such a tremendous blast, a star has to undergo a brutal, slow death. That's what sets these apart from when a star falls into a black hole in a typical tidal disruption event, which culminates in a powerful but brief flash. An ENT draws out the torture, forming a disk of the star's shredded entrails that glows for years. This aspect of a supermassive black hole's diet could tell us a lot about how they grew to their monstrous masses — a mystery that has long haunted astronomers — and how they stamped their name on a crucial period of the universe's history. "By observing these prolonged flares, we gain insights into black hole growth when the universe was half its current age and galaxies were busy places — forming stars and feeding their supermassive black holes ten times more vigorously than they do today," said coauthor Benjamin Shappee, an associate professor at IfA, in a statement. "These ENTs don't just mark the dramatic end of a massive star's life. They illuminate the processes responsible for growing the largest black holes in the universe," Hinkle added. More on astronomy: Scientists Spot Mysterious Object in Our Galaxy Pulsing Every 44 Minutes
Gizmodo
2 days ago
- Science
- Gizmodo
Astronomers Discover Most Energetic Cosmic Explosions Ever Observed
Astronomers in Hawaii have discovered a new kind of explosion, and they're the most energetic stellar explosions ever recorded. Meet 'extreme nuclear transients' (ENTs): when supermassive black holes tear apart stars at least three times heavier than the Sun, triggering an immense release of energy. An international team of researchers describes the discovery of this newly observed phenomenon in a study published Wednesday in the journal Science Advances, shedding light on events that will help astronomers study the distant universe. 'We've observed stars getting ripped apart as tidal disruption events for over a decade, but these ENTs are different beasts, reaching brightnesses nearly ten times more than what we typically see,' Jason Hinkle, lead author of the study and PhD student at the Institute for Astronomy at the University of Hawaii, said in a W. M. Keck Observatory statement. Tidal disruptions consist of supermassive black holes tearing apart any star that wanders too close, so ENTs are a kind of tidal disruption. 'Not only are ENTs far brighter than normal tidal disruption events, but they remain luminous for years, far surpassing the energy output of even the brightest known supernova explosions,' he added. Their discovery took place almost by accident. While searching for enduring flares projecting from the center of galaxies in data from the European Space Agency's Gaia mission, Hinkle came across two strange signals from 2016 and 2018, which started a multi-year investigation. At the same time, two separate teams found a comparable flare from 2020 in an astronomical survey called the Zwicky Transient Facility (ZTF). More data from the W. M. Keck Observatory in Hawaii confirmed the 2020 event's similarity to the two Gaia events. Given that these events unleashed more energy than any supernova known to science, Hinkle and his colleagues concluded that they weren't your average stellar explosions. The enormous energy release and the shape of the event's light curves indicated the presence of a supermassive black hole actively absorbing material, a process called accretion. Unlike regular black hole accretion, however—which sees nearby matter heat up and project irregular light—the astronomers discovered that these astrophysical events clearly involve a supermassive black hole systematically shredding and eating a giant star. ENTs represent the most energetic known explosions in the universe. Gaia18cdj, the team's strongest documented ENT, released 25 times more energy than the most energetic supernovae known to science. More broadly, each ENT releases as much energy as 100 Suns would emit over their entire 10-billion-year lifespans. For comparison, a regular supernova usually unleashes similar amounts of energy to a single Sun. 'These ENTs don't just mark the dramatic end of a massive star's life,' Hinkle explained. 'They illuminate the processes responsible for growing the largest black holes in the universe.' ENTs are also at least 10 million times rarer than supernovae. Nevertheless, their massive energy outputs will prove to be extremely useful for astronomers studying far-away massive black holes. 'Because they're so bright, we can see them across vast cosmic distances—and in astronomy, looking far away means looking back in time,' said Benjamin Shappee, study co-author and Associate Professor at the University of Hawaii's Institute for Astronomy. 'By observing these prolonged flares, we gain insights into black hole growth during a key era known as cosmic noon, 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.' From theories of black holes leading to white holes to the suggestion that the universe might exist in a black hole and that supermassive black holes could replace particle colliders, the recent study joins a host of research shedding light on one of the most mysterious components of our universe.
