\n<\/p>\n
Artistic concept of what the gas giant orbiting Alpha Centauri A could look like<\/p>\n
ESA\/Webb Copyright: NASA, ESA, CSA, STScI, R. Hurt (Caltech\/IPAC)<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
A giant planet the size of Saturn orbiting a sun-like star has potentially been identified in our nearest neighbouring stellar system, Alpha Centauri.<\/p>\n
At just four light years from Earth, Alpha Centauri is our closest star system. It is made up of three stars: Alpha Centauri A, Alpha Centauri B and a red dwarf star, Proxima Centauri. Researchers have long speculated Alpha Centauri could be home to a planet about as far away from a star as the Earth is to our sun \u2013 the liquid-water-friendly \u201chabitable zone\u201d \u2013 but confirming if any exists around the binary stars has proved challenging. That is because \u201c[the stars] are so bright, close, and move across the sky quickly\u201d, said Charles Beichman at the California Institute of Technology in a statement.<\/p>\n
But recent data collected by the James Webb Space Telescope\u2019s (JWST) Mid-Infrared Instrument (MIRI) suggests a gas giant as big as Saturn may have been found orbiting Alpha Centauri A, a sun-like star. The finding came as somewhat of a surprise. \u201cWebb was designed and optimised to find the most distant galaxies in the universe,\u201d said Beichman, not exoplanets. He said finding this planet required meticulous planning, involving multiple observations, analysis and computer modelling, which \u201cpaid off spectacularly\u201d.<\/p>\n
While previous strategies to find planets have relied on indirect measurements, JWST did something \u201cmuch more ambitious\u201d by directly capturing the light from the possible planet, says Alan Boss at Carnegie Science in Washington DC, who was not involved in the study. However, the potential planet wasn\u2019t visible in later observations.<\/p>\n
<\/p>\n \u201cWe are faced with the case of a disappearing planet!\u201d said Aniket Sanghi, also at Caltech, in a statement. The team simulated millions of potential orbits to investigate this mystery. \u201cWe found that in half of the possible orbits simulated, the planet moved too close to the star and wouldn\u2019t have been visible to Webb in both February and April 2025\u201d, when the later observations were made, he said.<\/p>\n As a gas giant, it could not support life as we know it. However, if confirmed, the finding could have major implications for our understanding of how planets form around stars. \u201cIts very existence in a system of two closely separated stars would challenge our understanding of how planets form, survive, and evolve in chaotic environments,\u201d said Sanghi. \u201cIt\u2019s also the most similar in temperature and age to the giant planets in our solar system, and nearest to our home, Earth.\u201d<\/p>\n