Get the key facts behind this story in our 1-minute read
Exciting evidence unveiled: The James Webb Space Telescope may have spotted a Saturn-like gas giant orbiting Alpha Centauri A, the closest Sun-like star to Earth
Closest potential exoplanet yet: This candidate – if confirmed – would be the nearest world discovered orbiting a star like our Sun in its habitable zone
Imaging with MIRI: Webb’s Mid-Infrared Instrument (MIRI), using a coronagraph to block out starlight, revealed the faint planetary signal near Alpha Centauri A
Planetary details: The object appears to have a similar mass to Saturn and orbits roughly two astronomical units from its star – twice Earth–Sun distance
Not habitable itself: As a gas giant, it couldn’t support life, but its location in the habitable zone makes the system intriguing
Disappearing act: The candidate, dubbed S1, was detected in 2024 but not seen again in follow-up Webb observations in early 2025, likely due to its orbit obscuring it temporarily
Orbital dynamics: Modeling suggests S1 could be on an eccentric orbit inclined relative to the Alpha Centauri A–B plane, with a 2–3-year period
Eyes on the sky: If this candidate is real, it may reappear around 2026–2027, giving astronomers a chance to confirm its existence, and possibly search for moons
Get the full story by reading our coverage of the potential planet discovered around Alpha Centauri
