Latest news with #SN2023zkd
Indian Express
2 days ago
- Science
- Indian Express
How AI is changing the way we discover cosmic events
Astronomers have recorded what could be the first known case of a massive star exploding while interacting with a black hole, a finding that could potentially lead to the discovery of an entirely new class of stellar explosions. The star, named SN 2023zkd, was first observed in July 2023, in California by the Zwicky Transient Facility. About 730 million light-years away, in a galaxy with minimal star formation activity, the star was detected using artificial intelligence (AI) designed to instantly identify unusual cosmic phenomena. According to a statement, the early warning allowed telescopes in space and around the world to begin observations immediately, capturing the event in its initial stages. Ashley Villar, an associate professor of astronomy at Harvard University and a co-author of the study, stated, '2023zkd shows some of the clearest signs we've seen of a massive star interacting with a companion before explosion. We think this might be part of a whole class of hidden explosions that AI will help us discover.' Initially, the star appeared to be a typical supernova — a bright flare gradually diminishing over time, signalling the death of a substantial star. However, astronomers observed that it brightened again months later. Historical data revealed that the system's brightness had been steadily increasing for nearly four years, or 1,500 days, prior to the explosion. Such an extended pre-explosion phase is uncommon and indicates the star was under considerable gravitational stress. Experts suggest that the most plausible scenario is that the star was caught in the orbit of a black hole. Evidence from light curves and spectra shows the star experienced two significant eruptions in the years before its end, releasing large amounts of gas. The initial light peak of the explosion was caused by the blast wave, while a slower, prolonged collision with a dense, disc-shaped cloud produced a second peak months later. Over time, the black hole's gravitational pull may have caused the star to collapse. The team also hypothesises that the star might have been consumed by the black hole before it could explode naturally. In that case, the supernova's light would have originated from debris colliding with the surrounding gas. Either way, a more massive black hole would result. SN 2023zkd 'is the strongest evidence to date that such close interactions can detonate a star,' said Alexander Gagliano, lead author of the study and a researcher at the Institute for Artificial Intelligence and Fundamental Interactions. 'We've known for some time that most massive stars are in binaries, but catching one in the act of exchanging mass shortly before it explodes is incredibly rare,' he said. The scientists believe these results demonstrate how AI can identify rare cosmic events in time for detailed scrutiny. They also emphasise the importance of future facilities like the Vera C. Rubin Observatory, which can survey the entire southern sky every few nights from its location in the Chilean Andes, over the next decade. When paired with real-time AI detection, Rubin Observatory's observations will enable astronomers to better understand the lifecycle of massive stars in binary systems by discovering and analysing more of these uncommon and complex phenomena. 'We're now entering an era where we can automatically detect these rare events as they occur, not just afterwards,' Gagliano stated. 'That means we can finally start linking the way stars live with how they die, and that's incredibly exciting,' he added. A report detailing these findings was published in the Astrophysical Journal on Wednesday, 13 August.
USA Today
2 days ago
- Science
- USA Today
A peculiar supernova prompts new theories about the cosmos
Scientists think a gigantic dying star tried to swallow a black hole. It didn't end well for the star, a new study says. A new discovery about what happens when a supernova – an exploding star – and a black hole collide could change the way scientists understand the lives and deaths of stars. The finding was the first time astrophysicists have observed a giant star exploding as the result, they believe, of its interaction with a dense black hole. The supernova was triggered by the intense gravitational stress of trying to "swallow" the black hole up, the study's authors say. The phenomenon may happen more than scientists realize, and new tools to observe supernova explosions could reveal other instances of black holes sparking supernovas, according to the lead study author. "If that is much more common, then it would transform the way we think about how stars explode," said Alex Gagliano, lead author of the study and fellow at the National Science Foundation Institute for Artificial Intelligence and Fundamental Interactions. One of the coolest parts of the discovery is that it was made possible by the use of artificial intelligence, or AI, Gagliano said. AI helped flag a star behaving unusually early on, which allowed the team to closely monitor as a surprising event unfolded. The study, published in the Astrophysical Journal, was conducted by a team led by the Center for Astrophysics, a collaboration between Harvard and the Smithsonian, and the Massachusetts Institute of Technology. It was part of the Young Supernova Experiment, which hopes to discover thousands of new cosmic explosions. What is a supernova? A black hole? A supernova is the spectacular explosion of a gigantic dying star. Stars – giant balls of gas – all have a life cycle, which can range from millions to trillions of years, according to NASA. When a huge star, several times the mass of the Sun, runs out of its nuclear fuel at its center, gravity's force takes over and it suddenly collapses, creating shock waves that cause the outer part of the star to explode into a supernova. A supernova typically leaves behind a very dense core. The very largest supernovas leave behind black holes, infamous for their great mystery. Black holes are points in the universe where gravity is so strong that nothing, not even light, can get out, NASA says. Their gravity is so strong because matter is squeezed into a tiny space. Because no light can escape, black holes are invisible, but scientists can spot evidence of them when they suck in matter and gas, which glow as they near the black hole. Sometimes black holes are observed to have companion stars, stars that orbit around them. That's the interaction researchers zeroed in on in this new discovery. The mystery of black holes: What's at the center of a black hole? Scientists have a sobering answer. Why is this exploding star so special? The discovery of the supernova dubbed SN 2023zkd was so unusual because it put together pieces of a puzzle that had never been seen together before, Gagliano said. Usually, a supernova explosion gets brighter over a period of a week or two before reaching its peak and then gets dimmer, he said. At first, SN 2023zkd looked like a typical supernova explosion, just a sudden peak of brightness. But it dimmed at an unusually slow rate afterward, causing an AI program to flag it for further study. Scientists watched its decline for months, and then came a very strange behavior: It began to brighten again in a second peak. To understand this, the researchers looked back at old archival data and discovered that before its first blast, the star had been slowly brightening for a period of about four years, an incredibly uncommon sight. All these factors combined pointed to one likely explanation. About 730 million light-years from Earth, SN 2023zkd had been a star locked in an orbital dance with a black hole, and as they gradually got closer to one another, the black hole pulled at the star's material, causing the gradually increasing glow, Gagliano said. At the moment of the explosion, the star and black hole became so close that the star couldn't survive anymore, he said. The extreme gravitational stress from the black hole caused the supernova explosion. The second peak of brightness happened when the explosion itself collided with a disc-like cloud of dust and gas leftover from the interaction between the star and the black hole. "It's been known for a long time that the majority of stars have companions that interact with them at some point during their lives... but we never really thought that this interaction played a leading role in driving the death of a star," Gagliano said. "That is something that is very new and exciting and I think will force us to revisit how we think about simulating the end of a star." How AI is helping astrophysicists make new discoveries The explosion was first discovered in July 2023, after the research team was alerted to unusually slow dimming of the glow of a supernova. The alert came from an AI program designed to scan the sky for all the supernovas and each morning report on any unusual activity. The alert allowed the researchers to continue to observe the supernova and see as it shockingly began to brighten again, indicating a second explosion. More: Black holes caught devouring massive stars in biggest explosion since Big Bang Were it not for the AI program, the initial explosion may have just looked observationally like many other supernovas and scientists would never have looked back to see its slow brightening and deduced that it was interacting with a black hole, Gagliano said. AI's role in sifting through mountains of data that human researchers can't and flagging anomalies is growing in several scientific fields, from medicine to astrophysics, Gagliano said. "One of the only reasons that we were able to make this discovery and understand how scientifically interesting it was was through the combination of researchers in machine learning and in astrophysics," he said.
Indian Express
2 days ago
- Science
- Indian Express
AI and astronomy: How artificial intelligence is changing the way we discover cosmic events
Astronomers have recorded what could be the first known case of a massive star exploding while interacting with a black hole, a finding that could potentially lead to the discovery of an entirely new class of stellar explosions. This star, named SN 2023zkd, was first observed in July 2023 in California by the Zwicky Transient Facility. About 730 million light-years away, in a galaxy with minimal star formation activity, the star was detected using innovative artificial intelligence (AI) technology designed to instantly identify unusual cosmic phenomena. According to a statement, the early warning allowed telescopes in space and around the world to begin observations immediately, capturing the event in its initial stages. Ashley Villar, an associate professor of astronomy at Harvard University and a co-author of the study, stated, '2023zkd shows some of the clearest signs we've seen of a massive star interacting with a companion before explosion. We think this might be part of a whole class of hidden explosions that AI will help us discover.' Initially, the star appeared to be a typical supernova — a bright flare gradually diminishing over time, signalling the death of a substantial star. However, astronomers observed that it brightened again months later. Historical data revealed that the system's brightness had been steadily increasing for nearly four years, or 1,500 days, prior to the explosion. Such an extended pre-explosion phase is uncommon and indicates the star was under considerable gravitational stress. Experts suggest that the most plausible scenario is that the star was caught in the orbit of a black hole. Evidence from light curves and spectra shows the star experienced two significant eruptions in the years before its end, releasing large amounts of gas. The initial light peak of the explosion was caused by the blast wave, while a slower, prolonged collision with a dense, disc-shaped cloud produced a second peak months later. Over time, the black hole's gravitational pull may have caused the star to collapse. The team also hypothesises that the star might have been consumed by the black hole before it could explode naturally. In that case, the supernova's light would have originated from debris colliding with the surrounding gas. Either way, a more massive black hole would result. SN 2023zkd 'is the strongest evidence to date that such close interactions can detonate a star,' said Alexander Gagliano, lead author of the study and a researcher at the Institute for Artificial Intelligence and Fundamental Interactions. 'We've known for some time that most massive stars are in binaries, but catching one in the act of exchanging mass shortly before it explodes is incredibly rare.' The scientists believe these results demonstrate how AI can identify rare cosmic events in time for detailed scrutiny. They also emphasise the importance of future facilities like the Vera C. Rubin Observatory, which can survey the entire southern sky every few nights from its location in the Chilean Andes, over the next decade. When paired with real-time AI detection, Rubin Observatory's observations will enable astronomers to better understand the lifecycle of massive stars in binary systems by discovering and analysing more of these uncommon and complex phenomena. 'We're now entering an era where we can automatically detect these rare events as they occur, not just afterwards,' Gagliano stated. 'That means we can finally start linking the way stars live with how they die, and that's incredibly exciting,' he added. A report detailing these findings was published in the Astrophysical Journal on Wednesday, 13 August.
NZ Herald
3 days ago
- Science
- NZ Herald
Astronomers explain one of the strangest explosions ever seen in our universe
Before the star could swallow the baby black hole, the black hole's gravitational forces caused the star to explode. 'That black hole has shaped that star's entire life' from its evolution to the type of explosion that ended its life, said Ashley Villar, a study author and professor at Harvard University. The discovery was published today in the Astrophysical Journal. It's not unusual to see these objects in close proximity to one another because most massive stars come in pairs or multiples, Villar said. Presumably, both objects in this scenario were once stars orbiting near each other before one evolved into a small black hole. Now orbiting around a black hole, the remaining star lost energy and was drawn in closer until it exploded into a new type of supernova never observed before. Most supernovas follow a typical fate: The star's core quickly collapses and sends a powerful shock wave through the outer layers of the star. The strong wave of energy causes a brief but bright flash of light. Meanwhile, the explosion's heat and pressure create radioactive elements, which decay and release energy. The energy is reabsorbed by surrounding material, causing it to glow and keeps the supernova bright for weeks to months. Over time, this glow dissipates. But this particular explosion, given the name SN 2023zkd per the International Astronomical Union, was unusual for several reasons. Firstly, the algorithm caught the supernova as it was dimming, but the light was fading at a much slower rate than expected. Secondly, scientists looked back at archival data and saw the supernova was actually brightening for about four years before it started to dim, which is an unusually long time for a supernova. Finally, as they continued to monitor the star, it unexpectedly brightened again. The team gathered ultraviolet to infrared data of the star from ground and space telescopes, capturing the sequence of both brightening events and running simulations in computer models. Based on the model scenarios, they determined the first brightening and subsequent decline was probably not powered by a radioactive decay seen in most supernovas. Instead, the researchers said the light source probably came from a traffic jam around the exploding star. It started as the distance between the massive star and black hole decreased. The black hole's strong gravity began unevenly ripping gases and dust from the star - like one side of a bedsheet getting caught in a vacuum cleaner. When the star started to explode, its blast wave collided with the dislodged gases around it and created the first flash. The second, later flash was caused by a slower but persistent crash with the thick, disk-like cloud. 'We think that the light source is actually from stuff hitting each other as it's trying to escape,' Villar said. 'That explosion hits that disk, and now we're seeing all this additional light.' The team considered another possible explanation for the light source, where the black hole tears apart the star before it has the chance to explode on its own. The black hole pulls in the star's debris, which crashes into the surrounding gas to generate a supernova-like flash. In either scenario, the star collapses to some degree. Scientists have previously theorised that some supernovas can be influenced by another object tugging on it, even capturing some data of supernovas with double brightening events. 'This is the first time when we have all of those pieces for the same explosion' from beginning to end, said Alex Gagliano, a co-author and researcher at Massachusetts Institute of Technology. He gives a large credit to their algorithm for catching the event early, detecting subtle anomalies about 100 days before scientists saw more obvious unusual activity. 'This is an exciting paper and I agree with the overall interpretation,' Danny Milisavljevic, an astrophysicist and associate professor at Purdue University who was not involved in the research, said in an email. He said the extraordinary properties of the light curve and slow changes in the star's spectral data provide compelling evidence that there is a black hole nearby. Theoretical scientists may continue to analyse these observations with different models for alternative explanations 'as is normal in the field,' said Or Graur, a professor of astrophysics at the University of Portsmouth who was not involved in the research. That's because the peculiar features of this explosion make it 'hard to easily slot it into one of the more common models' of supernovas. 'There are several weird supernovas that the community is continually observing, precisely because they're interesting and don't easily conform to our more common models,' said Graur, who has written a book about supernovas. 'The question is not whether it's plausible but whether it's probable - whether it's the best model to explain the data.' This observation is just scratching the cosmic surface of what's out there. The Vera C. Rubin Observatory - featuring the world's largest digital camera - will soon start a 10-year survey of the entire sky in the Southern Hemisphere. The telescope will capture thousands of supernovas each day, Villar said. The team plans to use the new AI algorithm, developed with the National Science Foundation's AI Institute for Artificial Intelligence and Fundamental Interactions, to quickly sift through data and detect more supernova events potentially like this one. 'Our dynamic universe is full of surprises. AI is how we keep up with the spectacle,' said Milisavljevic, who said many aspects of astronomy are being revolutionised by the technology. His own research has used AI to discover the most powerful optical explosion ever observed, nicknamed 'Scary Barbie'. Gagliano said the additional data can help scientists better understand the brightening sequence, which could help them forecast when a supernova may explode. 'We think that statistically we're overdue for a supernova in our own galaxy,' Gagliano said. 'There are many people that are trying to establish early warning systems so that as soon as our telescopes pick up on something unusual, we can all aim our telescopes in that location.' He added that the AI algorithm 'is somewhat similar in that it's an early warning system to pick up explosions that look somewhat unusual.' But there's no need to fear any impending supernova eruption in our galaxy, he said. People would be able to see the flash, but they wouldn't be in any danger. It would simply be a 'really fun light show', Villar said.
Yahoo
3 days ago
- Science
- Yahoo
Star Trying to Swallow a Black Hole May Have Triggered a New Type of Supernova
In 2023, astronomers recorded one of the most extraordinary space explosions they had ever seen. It took place some 750 million light-years away, flaring into the detectors of the Zwicky Transient Facility on 7 July. At first, it looked just like a normal supernova – the explosive death of a star – and astronomers named it SN 2023zkd. Six months later, a search for cosmic anomalies flagged the explosion as a little odd. A look back at data collected since its initial discovery revealed SN 2023zkd had done something really weird: it brightened again. Related: Space Could Be Littered With Eerie Transparent Stars Made Entirely of Bosons A new analysis offers up an absolutely Bizarro explanation: this strange sequence of events could be the result of a giant star trying to swallow a black hole like it's from Rand McNally. "Our analysis shows that the blast was sparked by a catastrophic encounter with a black hole companion, and is the strongest evidence to date that such close interactions can actually detonate a star," says astronomer Alexander Gagliano of the NSF Institute for Artificial Intelligence and Fundamental Interactions. Supernovae can happen in quite a variety of ways. They usually (but not always) involve the death of a massive star or the runaway thermonuclear explosions on a white dwarf. They're also relatively common, popping up across the Universe at a rate of a few hundred observable ones per year. Astronomers know more or less how they should play out: a flare of light that bursts onto the scene, followed by a gradual dimming that follows a pretty predictable curve over the ensuing weeks and months. Initial observations of SN 2023zkd looked relatively typical; a flare recorded by Zwicky was indicative of the early stages of a supernova. Then in January 2024, a tool designed to find unusual events in archives noted it was worth a second look. Data from different observatories around the world trained on the location had recorded the typical, fading lightcurve. Then it happened: 240 days after Zwicky discovered the event, it brightened again, nearly to the same level as the initial supernova. That's not something that most supernovae do, so Gagliano and his colleagues turned to archival observations of that sector of the sky to see if any behavior prior to the Zwicky detection could yield any clues, using machine learning to pick up signals humans might miss. They found that, for more than four years prior to the explosion, the object had been steadily brightening, with some strange fluctuations. This sort of long-term behavior isn't typical of stars about to explode. The scenario closest to the observations, the researchers determined, involved a massive dying star and a compact object such as a black hole, locked in a tight orbit. As they whirled around each other in a decaying orbit, the star shed a great deal of its mass, which in turn started to glow. Eventually, the researchers believe, the two objects drew close enough together that the star exerted its gravitational pull to subsume the black hole; however, the gravitational pull exerted by the black hole stressed the star to such a degree that it triggered a supernova. The first peak in brightness was from the blast of the supernova colliding with low-density gas around the system. The second peak was from a slower, more sustained collision with the thick cloud of material ejected by the star in its final years. The strange fluctuations prior to the explosion were indicative of a system stressed by the presence of a black hole. This is not as impossible as it might sound. A black hole only has as much gravity as a star of comparable mass; if you're at a reasonable distance, as you would be for a star, things behave the same way. However, a black hole is so compact that you can get much closer, to the point where you would be inside a star of comparable mass, the strength of its gravitational field increasing as you go. The Sun, for instance, is about 1.4 million kilometers (865,000 miles) across. The event horizon of a black hole with the same mass as the Sun is about 6 kilometers across. So, if the star in the binary had a greater mass than the black hole, then it would be considered that the star pulled the black hole in, before the black hole's extreme close gravity brought the star to a sticky end. The other possibility is that the black hole completely devoured the star before it could explode; both scenarios exhibit the same collision with the material around the system. Either way, the end result is a bigger black hole. "We're now entering an era where we can automatically catch these rare events as they happen, not just after the fact," Gagliano says. "That means we can finally start connecting the dots between how a star lives and how it dies, and that's incredibly exciting." The research is due to be published in The Astrophysical Journal, and a preprint is available on arXiv. Related News Interstellar Object 3I/ATLAS Seen in Stunning New Hubble Image Fast Radio Burst Source Traced Record Distance Across The Universe Tiny 'Coral' Discovered by Rover in Martian Crater Solve the daily Crossword
