JWST Detects Possible Gas Giant Orbiting Nearest Sun-Like Star Alpha Centauri

Astronomers using NASA's James Webb Space Telescope have found strong evidence of a Saturn-sized gas giant candidate orbiting Alpha Centauri A, part of the closest star system to Earth beyond our own sun. This candidate planet, referred to as S1, lies within the habitable zone of Alpha Centauri A, though as a gas giant it is unlikely to host life itself, but potentially habitable moons could exist. The discovery, detailed in two forthcoming papers in The Astrophysical Journal Letters, was made possible through direct imaging using Webb's Mid-Infrared Instrument and coronagraphic masks to block the overwhelming light from the bright nearby stars. The Alpha Centauri system's complexity, including its triple-star composition and intense star brightness, has made confirming planets difficult, requiring sophisticated imaging techniques and multi-year observations. The candidate planet’s position aligns with a tentative detection from 2019, though follow-up observations have been inconclusive, possibly due to the planet's orbital movement. These findings mark an important step toward studying planetary systems nearest to Earth and may pave the way for future robotic or human exploration.