Latest news with #AlphaCentauriA
Economic Times
3 days ago
- Science
- Economic Times
Is there a Saturn-sized world hiding beside our nearest star? James Webb spots a new world next door
Synopsis Astronomers using the James Webb Space Telescope believe they may have found a Saturn-sized planet orbiting Alpha Centauri A, one of the closest stars to Earth. The world, temporarily glimpsed in 2024, vanished from later Webb observations, sparking simulations to explain its disappearance. If real, it sits within the star's habitable zone, although as a gas giant it cannot support life directly. Still, its moons could. Confirmation would mark the closest planet ever directly imaged around a Sun-like star. NYT News Service An infrared image from the James Webb Space telescope, using a coronagraphic mask to block the bright glare from Alpha Centauri A (represented at center), that reveals a potential planet (circled at left) orbiting the star. Astronomers have found strong evidence that a gassy Jupiter-size world is orbiting Alpha Centauri A, one of three stars in the solar system closest to our own. (NASA via The New York Times) Scientists have announced signs of a possible new planet around Alpha Centauri A, part of the star system nearest to us. The candidate, informally named Alpha Centauri Ab, would orbit in the habitable zone, where liquid water could exist. The find was made using the James Webb Space Telescope in August 2024. Webb's Mid-Infrared Instrument, equipped with a coronagraph to block out starlight, revealed a faint object orbiting at around twice the Earth–Sun distance. At that separation, a planet could be warm enough for water, a tantalising prospect so close to home. What complicates the story is that the planet seemed to vanish. Webb picked up the faint signal in 2024 but saw nothing in follow-up observations in February and April 2025.'We are faced with the case of a disappearing planet!' said Aniket Sanghi of the California Institute of Technology, who led the study. His team ran computer models of millions of possible orbits to see what might explain the signal. 'We found that in half of the possible orbits simulated, the planet moved too close to the star and wouldn't have been visible to Webb in both February and April 2025,' Sanghi models also lined up with a 2019 detection by the European Southern Observatory's Very Large Telescope, which adds weight to the idea that this planet might be real, simply slipping in and out of view as it traces an elliptical path around its star. Webb's data points to a world about the size of Saturn. Unlike Earth, it would be a gas giant, and so not directly habitable. But astronomers note that large moons around such planets could, in theory, provide conditions suitable for Beichman of NASA's Jet Propulsion Laboratory described the potential significance. 'This would become a touchstone object for exoplanet science, with multiple opportunities for detailed characterisation by Webb and other observatories,' he Centauri is not just any star system. Sitting about four light years away, it is the nearest trio of stars to us, made up of Alpha Centauri A, Alpha Centauri B, and Proxima Centauri. Proxima already has known planets, one of which orbits in its habitable zone, but this new candidate would be the closest planet ever directly imaged around a Sun-like star. That makes it a prime target for studying how planetary systems form and evolve near stars like our system itself is tricky to observe. Alpha Centauri A and B sit close together, their light overlapping. Untangling faint planetary signals from the glare of two bright stars is a technical feat, and part of the reason astronomers tread carefully before declaring this a confirmed case is not closed. With Webb's observations limited by the timing of its view and the planet's possible orbit, astronomers will need more chances to watch Alpha Centauri A. If the planet exists, it should eventually emerge again from the star's upcoming Nancy Grace Roman Space Telescope, expected to launch in 2027, could add critical evidence by providing visible-light observations to complement Webb's infrared now, the world nearest to us remains a mystery. A Saturn-sized neighbour in the habitable zone of Alpha Centauri A might be waiting to be confirmed. As Sanghi put it, the planet may have slipped from sight, but if it is real, it should reveal itself again in the years ahead.
Time of India
3 days ago
- Science
- Time of India
Is there a Saturn-sized world hiding beside our nearest star? James Webb spots a new world next door
Scientists have announced signs of a possible new planet around Alpha Centauri A , part of the star system nearest to us. The candidate, informally named Alpha Centauri Ab, would orbit in the habitable zone , where liquid water could exist. The find was made using the James Webb Space Telescope in August 2024. Webb's Mid-Infrared Instrument, equipped with a coronagraph to block out starlight, revealed a faint object orbiting at around twice the Earth–Sun distance. At that separation, a planet could be warm enough for water, a tantalising prospect so close to home. A signal that disappeared What complicates the story is that the planet seemed to vanish. Webb picked up the faint signal in 2024 but saw nothing in follow-up observations in February and April 2025. 'We are faced with the case of a disappearing planet!' said Aniket Sanghi of the California Institute of Technology, who led the study. His team ran computer models of millions of possible orbits to see what might explain the signal. 'We found that in half of the possible orbits simulated, the planet moved too close to the star and wouldn't have been visible to Webb in both February and April 2025,' Sanghi explained. The models also lined up with a 2019 detection by the European Southern Observatory's Very Large Telescope, which adds weight to the idea that this planet might be real, simply slipping in and out of view as it traces an elliptical path around its star. Live Events What the data suggests Webb's data points to a world about the size of Saturn. Unlike Earth, it would be a gas giant , and so not directly habitable. But astronomers note that large moons around such planets could, in theory, provide conditions suitable for life. Charles Beichman of NASA 's Jet Propulsion Laboratory described the potential significance. 'This would become a touchstone object for exoplanet science, with multiple opportunities for detailed characterisation by Webb and other observatories,' he said. Why Alpha Centauri matters Alpha Centauri is not just any star system. Sitting about four light years away, it is the nearest trio of stars to us, made up of Alpha Centauri A, Alpha Centauri B, and Proxima Centauri . Proxima already has known planets, one of which orbits in its habitable zone, but this new candidate would be the closest planet ever directly imaged around a Sun-like star. That makes it a prime target for studying how planetary systems form and evolve near stars like our own. The system itself is tricky to observe. Alpha Centauri A and B sit close together, their light overlapping. Untangling faint planetary signals from the glare of two bright stars is a technical feat, and part of the reason astronomers tread carefully before declaring this a confirmed discovery. The case is not closed. With Webb's observations limited by the timing of its view and the planet's possible orbit, astronomers will need more chances to watch Alpha Centauri A. If the planet exists, it should eventually emerge again from the star's glare. NASA's upcoming Nancy Grace Roman Space Telescope, expected to launch in 2027, could add critical evidence by providing visible-light observations to complement Webb's infrared data. For now, the world nearest to us remains a mystery. A Saturn-sized neighbour in the habitable zone of Alpha Centauri A might be waiting to be confirmed. As Sanghi put it, the planet may have slipped from sight, but if it is real, it should reveal itself again in the years ahead.
Yahoo
5 days ago
- Science
- Yahoo
Our Closest Sun-Like Star May Host a World Where Life Could Thrive
There may be a habitable world at the Sun's closest solar twin. In the complex space inhabited by the Alpha Centauri triple star system, JWST has just discerned the presence of a giant exoplanet orbiting Alpha Centauri A, the most Sun-like of the three stars. Moreover, that exoplanet is in the star's habitable zone – the perfect distance from the star for liquid water to pool. But wait – there's more. Evidence of the prospective world, which is tentatively known as Alpha Centauri Ab, was discovered using direct imaging in what could be a significant breakthrough for exoplanet science. Related: "If confirmed, the potential planet seen in the Webb image of Alpha Centauri A would mark a new milestone for exoplanet imaging efforts," says astrophysicist Aniket Sanghi of the California Institute of Technology. "Of all the directly imaged planets, this would be the closest to its star seen so far. It's also the most similar in temperature and age to the giant planets in our Solar System, and nearest to our home, Earth." The Alpha Centauri system is located just 4 light-years away, a triple system made up of the binary pair Alpha Centauri A and Alpha Centauri B, orbited at a greater distance by the red dwarf star Proxima Centauri. Other exoplanets are already known in the system. Three have been found orbiting Proxima Centauri, including one within the star's habitable zone. But the conditions around red dwarf stars – which tend towards the tempestuous – may be less hospitable than those around stars like the Sun. The detection of worlds in the central binary has been more difficult to accomplish. "With this system being so close to us, any exoplanets found would offer our best opportunity to collect data on planetary systems other than our own," says astronomer Charles Beichman, director of the NASA Exoplanet Science Institute at Caltech. "Yet, these are incredibly challenging observations to make, even with the world's most powerful space telescope, because these stars are so bright, close, and move across the sky quickly." To date, Alpha Centauri B remains without a known world. However, glimmers of something have been spotted in orbit around Alpha Centauri A, the brightest of the three stars and belonging to the same G-type class as the Sun. In 2021, a team of astronomers led by Kevin Wagner of the University of Arizona announced a tentative detection of an exoplanet in the habitable zone of Alpha Centauri A, identified using direct imaging. Most exoplanets are found using indirect methods, such as looking for regular dips in starlight, blocked by the orbiting exoplanet, or changes in starlight associated with the gravitational effect of the exoplanet's presence. Sanghi, Beichman, and their colleagues used JWST to look for further evidence of this world, taking their first observations in August 2024, using a coronagraph to mask the light from Alpha Centauri A. After subtracting the light from Alpha Centauri B, their results showed a faint point source, at around twice the distance from Alpha Centauri as Earth is from the Sun. But follow-up observations conducted in February and April of 2025 revealed no such object. "We are faced with the case of a disappearing planet!" Sanghi explains. "To investigate this mystery, we used computer models to simulate millions of potential orbits, incorporating the knowledge gained when we saw the planet, as well as when we did not." These simulations also included the sighting of Wagner and his team. In about half the simulations, the exoplanet was too close to the star to be detected, its presence drowned out by all the bright light – supporting the case for Alpha Centauri Ab. This world, the researchers determined, would have a radius of around 1 to 1.1 Jupiters, a mass between 90 and 150 Earths, comparable to Saturn's 95-Earth mass, and orbit at about twice the Earth-Sun distance, squarely in the habitable zone. This set of properties describes a world that would have to be a gas giant, which places its potential habitability into question. However, gas giants in the Solar System are lousy with moons that could have habitable conditions – so the nature of the exoplanet doesn't rule out life around Alpha Centauri A. However, more work needs to be done to confirm the existence of Alpha Centauri Ab, and figure out how the heck it even formed in the complex gravitational environment of the Alpha Centauri system. "Its very existence in a system of two closely separated stars would challenge our understanding of how planets form, survive, and evolve in chaotic environments," Sanghi says. The finding is detailed in two papers in The Astrophysical Journal Letters. They can be found here and here. Related News JWST Delivers Bad News About Life on TRAPPIST-1 Planet Record US$5.3M Sale of Largest Mars Rock Sparks Global Dispute Earliest Black Hole Ever Confirmed Could Explain Mysterious Red Dots Solve the daily Crossword
NDTV
6 days ago
- Science
- NDTV
A New 'Earth' Next Door? Scientists Detect Possible Habitable Planet Around Closest Sun-Like Star
Astronomers may have uncovered a promising new candidate for extraterrestrial life, right in our stellar neighbourhood. Using the James Webb Space Telescope (JWST), researchers have detected what appears to be a giant exoplanet orbiting Alpha Centauri A, the closest solar twin to our Sun. Located within the Alpha Centauri triple star system, this planet, tentatively named Alpha Centauri Ab, occupies the star's habitable zone, the optimal distance for liquid water to exist on its surface. The discovery, made possible through direct imaging, marks a significant milestone in exoplanet science. If confirmed, this would be the first time such a potentially habitable planet has been identified around our nearest Sun-like neighbour. Scientists believe that Alpha Centauri Ab's location in the "Goldilocks zone" could make it a prime target in the search for life beyond Earth. The finding also underscores JWST's unprecedented capabilities in spotting and studying distant worlds that were once invisible to astronomers. "We found that in half of the possible orbits simulated, the planet moved too close to the star and wouldn't have been visible to Webb in both February and April 2025," said astrophysicist Aniket Sanghi of the California Institute of Technology. Based on the brightness of the planet in the mid-infrared observations and the orbit simulations, researchers say it could be a gas giant approximately the mass of Saturn orbiting Alpha Centauri A in an elliptical path varying between one and two times the distance between the Sun and Earth. "If confirmed, the potential planet seen in the Webb image of Alpha Centauri A would mark a new milestone for exoplanet imaging efforts," Sanghi says. "Of all the directly imaged planets, this would be the closest to its star seen so far. It's also the most similar in temperature and age to the giant planets in our solar system and nearest to our home, Earth," he says. "Its very existence in a system of two closely separated stars would challenge our understanding of how planets form, survive, and evolve in chaotic environments." If confirmed by additional observations, the team's results could transform the future of exoplanet science. "This would become a touchstone object for exoplanet science, with multiple opportunities for detailed characterisation by Webb and other observatories," said Charles Beichman of NASA's Jet Propulsion Laboratory and the NASA Exoplanet Science Institute at Caltech's IPAC astronomy centre, co-first author on the new papers.
Forbes
09-08-2025
- Science
- Forbes
NASA's Webb May Have Found A Planet Around The Closest Sun-Like Star
NASA has announced the probable discovery of a giant planet orbiting Alpha Centauri A, one of the closest stars to the solar system. If confirmed, it would be the nearest planet ever detected around a sun-like star. Although it's in the habitable zone of the star, it's a gas giant, so it would not support life as we know it. Astronomers using the James Webb Space Telescope found a planet while observing Alpha Centauri, a system of three stars orbiting each other — binary stars Alpha Centauri A and B, along with the red dwarf star Proxima Centauri. They're just four light-years from the solar system. Breakthrough Discovery It's been known for some time that three planets are orbiting Proxima Centauri, but planets around Alpha Centauri A — a star much like the sun — have until now proved elusive. The breakthrough came when astronomers used a coronagraph — a disk to block the bright starlight — from Alpha Centauri A, revealing a faint object around it. Around 10,000 times dimmer than the star, the planet is about twice as far from its star as Earth is from the sun. The evidence was published across two papers in The Astrophysical Journal Letters. Possible Saturn-Mass World Based on brightness and simulations, researchers believe the object could be a gas giant about the mass of Saturn — though additional observations will be needed to confirm the planet's existence. The discovery at Alpha Centauri A — the third brightest star in the night sky — could be a massive breakthrough for planetary scientists wanting to learn more about exoplanets (planets orbiting stars other than the sun). 'With this system being so close to us, any exoplanets found would offer our best opportunity to collect data on planetary systems other than our own,' said Charles Beichman, NASA's Jet Propulsion Laboratory and the NASA Exoplanet Science Institute at Caltech's IPAC astronomy center, co-first author on the new papers. 'Yet, these are incredibly challenging observations to make, even with the world's most powerful space telescope, because these stars are so bright, close, and move across the sky quickly.' Disappearing Planet? However, it's not entirely clear that this planet exists at all. First sighted in 2019 by the European Southern Observatory's Very Large Telescope, astronomers spotted it in August 2024, using the coronagraph in Webb's MIRI instrument. However, light from Alpha Centauri B made it a difficult observation. Attempts to confirm the planet's existence in February 2025 and April 2025 did not succeed. Researchers were not surprised, having modelled where the planet ought to be on its elliptical orbit. 'We found that in half of the possible orbits simulated, the planet moved too close to the star and wouldn't have been visible to Webb in both February and April 2025,' said Ph.D. student Aniket Sanghi of Caltech in Pasadena, California, the co-first author on the two papers covering the team's research. 'Its very existence in a system of two closely separated stars would challenge our understanding of how planets form, survive, and evolve in chaotic environments.' It's hoped that NASA's Nancy Grace Roman Space Telescope, set to launch as soon as 2026, could complement Webb's infrared data with visible-light observations, helping confirm the planet and figure out its size and composition. Either way, Alpha Centauri A's gas giant will be a prime target for the next generation of astronomers and telescopes. Wishing you clear skies and wide eyes.
