Latest news with #IfA
NDTV
4 days ago
- Science
- NDTV
Astronomers Uncover Most Powerful Explosion Since The Big Bang
Astronomers from the University of Hawai'i's Institute for Astronomy have identified a new class of cosmic explosions, termed "extreme nuclear transients" (ENTs), marking the most energetic events observed since the Big Bang. These phenomena occur when massive stars, at least three times the mass of our Sun, are torn apart by supermassive black holes at the centres of distant galaxies. The resulting explosions release energy equivalent to what 100 Suns would emit over their entire lifespans, making them visible across vast cosmic distances. This discovery offers new insights into the dynamic interactions between stars and black holes in the universe. The team's findings were detailed today in the journal Science Advances. "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," said Jason Hinkle, in a statement, who led the study as the final piece of his doctoral research at IfA. "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." The immense luminosities and energies of these ENTs are truly unprecedented. The most energetic ENT studied, named Gaia18cdj, emitted an astonishing 25 times more energy than the most energetic supernovae known. While typical supernovae emit as much energy in just one year as the sun does in its 10 billion-year lifetime, ENTs radiate the energy of 100 suns over a single year. As per a news release by W M Keck Observatory, ENTs were first uncovered when Hinkle began a systematic search of public transient surveys for long-lived flares emanating from the centres of galaxies. He identified two unusual flares in data from the European Space Agency's Gaia mission that brightened over a timescale much longer than known transients and without characteristics common to known transients. "Gaia doesn't tell you what a transient is, just that something changed in brightness," said Hinkle. "But when I saw these smooth, long-lived flares from the centres of distant galaxies, I knew we were looking at something unusual."
Yahoo
4 days ago
- Science
- Yahoo
Astronomers Just Discovered The Biggest Explosions Since The Big Bang
A never-before-seen type of giant space explosion – the biggest bangs since the Big Bang – has been accidentally captured by the Gaia space telescope. From the hearts of distant galaxies, the mapping telescope recorded sudden, extreme increases in brightness – colossal flares of light that lingered far longer than any such flares had been known to previously. These blasts were calculated to release as much energy as 100 Suns would over the course of their combined lifetimes. Analysis of that light revealed something that was both new and familiar at the same time: stars being torn apart by black holes, but on a scale we hadn't observed before. Each star was a large one, at least three times as massive as the Sun; and each black hole was a supermassive beast lurking in the center of the star's host galaxy. Such events are usually known as tidal disruption events, or TDEs. Astrophysicists are calling these new ones 'extreme nuclear transients' – ENTs for short. "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," says astrophysicist Jason Hinkle of the University of Hawaiʻi's Institute for Astronomy (IfA). "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." The rather tame term 'tidal disruption' is used to describe what gravitational forces do to an object that gets too close to a black hole. At a certain point, the power of the external gravitational field surpasses the gravity holding an object together, and it comes apart in a wild scream of light before at least partially falling into the great unknown beyond the black hole's event horizon. There are telescopes trained on the sky to catch these screams, applying a wide field of view to take in as much of the sky as possible, waiting for those unpredictable flares that denote the death throes of an unlucky star. Astronomers have managed to observe a good number of TDEs, and know roughly how they should play out. There's a sudden brightening in a distant galaxy, with a light curve that rises to a rapid peak before gradually fading over the course of weeks to months. Astronomers can then analyze that light to determine properties such as the relative masses of the objects involved. Gaia was a space telescope whose mission was to map the Milky Way in three dimensions. It spent a great deal of time staring at the sky to capture precise parallax measurements of the stars in the Milky Way. On occasion, however, it managed to exceed its mission parameters. When combing through Gaia data, Hinkle and his colleagues found two strange events: Gaia16aaw, a flare recorded in 2016; and Gaia18cdj, which the telescope caught in 2018. Both events bore a strong similarity to an event recorded by the Zwicky Transient Facility in 2020. Because that event was so insanely powerful, and because it was given the designation ZTF20abrbeie, astronomers nicknamed it "Scary Barbie". Hinkle and his team determined that Gaia16aaw and Gaia18cdj are the same kind of event as Scary Barbie, and set about trying to figure out what caused them. They ruled out supernova explosions – the events were at least twice as powerful as any other known transients, and supernovae have an upper brightness limit. A supernova, the team explained, typically releases as much light as the Sun will in its entire, 10-billion-year lifespan. The output of an ENT, however, is comparable to the lifetime output of 100 Suns all rolled together. Rather, the properties of the ENT events, the researchers found, were consistent with TDEs – just massively scaled up. That includes how much energy is expended, and the shape of the light curve as the event brightens and fades. ENTs are incredibly rare – the team calculated that they are around 10 million times less frequent than supernovae – but they represent a fascinating piece of the black hole puzzle. Supermassive black holes are millions to billions of times the mass of the Sun, and we don't have a clear idea of how they grow. ENTs represent one mechanism whereby these giant objects can pack on mass. "ENTs provide a valuable new tool for studying massive black holes in distant galaxies. Because they're so bright, we can see them across vast cosmic distances – and in astronomy, looking far away means looking back in time," says astrophysicist Benjamin Shappee of IfA. "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 [and] when galaxies were happening places – forming stars and feeding their supermassive black holes 10 times more vigorously than they do today." The research has been published in Science Advances. Titan's Atmosphere 'Wobbles Like a Gyroscope' – And No One Knows Why A 'Crazy Idea' About Pluto Was Just Confirmed in a Scientific First A Giant Mouth Has Opened on The Sun And Even It Looks Surprised
Yahoo
5 days ago
- Science
- Yahoo
Astronomers detect most powerful explosions since Big Bang
At any given time across the universe, massive cosmic bodies are releasing incomprehensible amounts of energy. Stars burn like celestial nuclear fusion reactors, quasars emit thousands of times the luminosity of the Milky Way galaxy, and asteroids slam into planets. But all of these pale in comparison to a new class of events discovered by researchers at the University of Hawai'i's Institute for Astronomy (IfA). According to their findings published June 4 in the journal Science Advances, it's time to classify the universe's most energetic explosions as extreme nuclear transients–or ENTs. ENTs are as devastating as they are rare. They only occur when a massive star at least three times heavier than the sun drifts too close to a supermassive black hole. The colliding forces subsequently obliterate the star, sending out plumes of energy across huge swaths of space. Similar events known as tidal disruption events (TDEs) are known to occur on a (comparatively) smaller scale, and have been documented for over a decade. But ENTs are something else entirely. 'ENTs are different beasts,' study lead author and astronomer Jason Hinkle explained in an accompanying statement. '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 was first tipped off to ENTs while looking into transients—longlasting flares that spew energy from a galaxy's center. Two particularly strange examples captured by the European Space Agency's Gaia mission caught his eye. The pair of events brightened over a much longer timeframe than previously documented transients, but lacked some of their usual characteristics. 'Gaia doesn't tell you what a transient is, just that something changed in brightness,' Hinkle said. 'But when I saw these smooth, long-lived flares from the centers of distant galaxies, I knew we were looking at something unusual.' Hinkle soon reached out to observatory teams around the world for what would become a multiyear project to understand these anomalies. In the process, a third suspect was detected by the Zwicky Transient Facility at the Palomar Observatory in San Diego. After months of analysis, Hinkle and collaborators realized they were witnessing something unprecedented. The ENTs analyzed by astronomers displayed smoother, longer lasting flares that pointed towards something very particular—a supermassive black hole accreting a giant, wayward star. This contrasts with a more standard black hole that typically acquires its material and energy unpredictably, resulting in irregular brightness fluctuations. The energy and luminosity of an ENT boggles the mind. The most powerful ENT documented in Hinkle's study, Gaia18cdj, generated 25 times more energy than the most powerful known supernovae. For reference, a standard supernova puts out as much energy in a single year as the sun does across its entire 10 billion year lifespan. Gaia18cdj, meanwhile, manages to give off 100 suns' worth of energy over just 12 months. The implications of ENTs and their massive energy surges go far beyond their impressive energy outputs. Astronomers believe they contribute to some of the most pivotal events in the cosmos. '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,' said Hinkle. From here on Earth, ENTs can also help researchers as they continue studying massive, distant 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,' explained study co-author and astronomer Benjamin Shappee. 'By observing these prolonged flares, we gain insights into black hole growth when the universe was half its current age… forming stars and feeding their supermassive black holes 10 times more vigorously than they do today.' There's a catch for astronomers, however. While supernovae are relatively well-documented, ENTs are estimated to occur at least 10 million times less often. This means that further study requires consistent monitoring of the cosmos backed by the support of international governments, astronomical associations, and the public.
