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Indian Express
25 minutes 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.
Indian Express
2 hours 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.
Yahoo
19 hours 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
Yahoo
13-06-2025
- Science
- Yahoo
Missing link star? Why this 'teenage vampire' white dwarf has scientists so excited
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have discovered the "missing link" connecting the death of sunlike stars to the birth of white dwarf stellar remnants, in the form of a "teenage vampire" white dwarf. This vampire isn't interested in the blood that runs through your veins, though. The white dwarf in question, designated Gaia22ayj and located around 8,150 light-years from Earth, is ravenously feeding on stellar plasma from a companion star. The team that made this discovery observed the white dwarf using the Zwicky Transient Facility (ZTF) at the Palomar Observatory in California. The researchers scanned the night sky over the Northern Hemisphere, hunting "transients" — astronomical bodies undergoing rapid change. Gaia22ayj originally attracted the attention of astronomers with its rapidly pulsing signal, which led to it being classified as a detached double white dwarf binary — two white dwarf stars orbiting each other. However, this theory didn't quite match further observations of Gaia22ayj, which revealed it to be one of the most extreme pulsating objects ever seen, increasing in brightness by 700% over just a 2-minute span. That's because Gaia22ayj is actually a white dwarf feeding on a companion star, with this binary in a rare and short-lived phase of its life (or should that be death). Stars die after they use up the fuel needed for nuclear fusion. What kind of death, and afterlife, they experience depends on their mass. Stars with masses above eight times that of the sun die in violent supernova explosions and then become either highly dense neutron stars or black holes. Stars with masses closer to that of the sun don't "go nova," instead undergoing more muted transformations into white dwarfs. Our own sun will experience this latter transformation in around six billion years after shedding most of its mass during a swollen red giant phase, eventually sputtering out as a smoldering stellar ember. However, around half of all stars with masses similar to that of the sun have a binary companion star. And, if their companion stars get too close, white dwarfs can get a second burst of life by stripping them of stellar material. That vampiric mass transfer process is exactly what seems to be happening between the white dwarf of Gaia22ayj and its companion star. Gaia22ayj initially confused astronomers. The way that its light intensity varied over time — its light curve— made no sense for a detached double white dwarf binary. This led Tony Rodriguez, a graduate student in the California Institute of Technology's ZTF Stellar Group, to question why the light curve would take the shape it did. Gathering more data, Rodriguez and colleagues realized that Gaia22ayj is likely a white dwarf orbited by a "normal" low-mass star, not a second white dwarf. And they further determined that Gaia22ayj is highly magnetic, with its white dwarf component spinning at a rapid rate. This reminded them of a white dwarf pulsar, a highly magnetic dead star that sweeps electromagnetic radiation across the universe as it spins, like a cosmic lighthouse. However, the vampiric feeding process found in Gaia22ayj isn't something usually associated with white dwarf pulsars. The team eventually concluded that Gaia22ayj is a missing link in the life cycle of white dwarf pulsars, a rare and short-lived early phase of these objects. "We have already seen two infant systems, white dwarf stars in a binary system whose rapid spin builds up a strong magnetic field. And we had seen lots of adult star systems where the white dwarf star was spinning very slowly," Rodriguez said in a statement. "But this was the first star we've seen that is right in the middle of its 'teenage' phase, when it has already established a strong magnetic field and is just beginning to funnel matter from the companion star onto itself," he added. "We have never before caught a system in the act of spinning so rapidly but also slowing down dramatically, all while gaining mass from its companion." This discovery is even more exciting because this phase lasts for just around 40 million years. That might sound like an incredibly long period of time, but it's relatively short when considering that stars like the sun live for around 10 billion years before they even transform into white dwarfs. Thus, this "teenage phase" accounts for just 0.4% of a star's lifetime. For context, if the star were an average human, this teenage phase would last just around 107 days. Hardly enough time to paint your bedroom black. Related Stories: — Puffy white dwarfs could shed light on mysterious dark matter. Here's how. — White dwarfs are 'heavy metal' zombie stars endlessly cannibalizing their dead planetary systems — 'Daredevil' white dwarf star could be closest-known object to a weird black hole "The data taken at the W. M. Keck Observatory provided firm evidence that this system had a strong magnetic field and was funneling matter onto the white dwarf," Rodriguez said. "Additional data from the unique instruments available at Palomar Observatory showed that this system is, remarkably, slowing down." The team's research was published in February in the journal Publications of the Astronomical Society of the Pacific.
Al Etihad
10-06-2025
- Science
- Al Etihad
European Space Agency's new asteroid hunter opens its eye to sky
10 June 2025 12:03 SICILY (ALETIHAD) The European Space Agency's (ESA) newest planetary defender has opened its 'eye' to the cosmos for the first time. The Flyeye telescope's 'first light' marks the beginning of a new chapter in how to scan the skies for new near-Earth asteroids and by an insect's compound eye, ESA and OHB Italia designed Flyeye to capture a region of the sky more than 200 times as large as the full Moon in a single exposure – much larger than a conventional will use this wide field of view to automatically survey the sky each night independent from human operation and identify new asteroids that could pose a hazard to Earth. 'In the future, a network of up to four Flyeye telescopes spread across the northern and southern hemispheres will work together to further improve the speed and completeness these automatic sky surveys and to reduce the dependence on good weather at any individual site,' said ESA's Ernesto Doelling, Flyeye Project Manager.'The earlier we spot potentially hazardous asteroids, the more time we have to assess them and, if necessary, prepare a response,' said Richard Moissl, Head of ESA's Planetary Defence Office. 'ESA's Flyeye telescopes will be an early-warning system, and their discoveries will be shared with the global planetary defence community.'ESA's Near-Earth Object Coordination Centre (NEOCC) will verify any potential new asteroid detections made by the Flyeye telescopes and submit the findings to the Minor Planet Centre, Earth's hub for asteroid observational data. Astronomers, including experts from the NEOCC, will then carry out follow-up observations to further assess the hazard that the object may Aceti, Managing Director at OHB Italia, explained, 'The unique optical design of the Flyeye telescope is optimised for conducting large sky surveys while maintaining high image quality throughout the wide field of view."He added that the telescope is equipped with a one-metre primary mirror, which efficiently captures incoming light. This light is then divided into 16 separate channels, each equipped with a camera capable of detecting very faint objects. This enables simultaneous high-sensitivity observations over a large region of the sky. During operations, Flyeye's observation schedule will be optimised to consider factors such as Moon brightness and the work of other survey telescopes such as the NASA-funded ATLAS telescopes, the Zwicky Transient Facility and the upcoming Vera Rubin Telescope.
