Possible Saturn-mass planet near Alpha Centauri A remains unconfirmed despite Webb hints
The James Webb Space Telescope briefly detected a faint source near Alpha Centauri A in 2024 (S1) that could be a Saturn-mass planet in the system’s habitable zone, but follow-up observations in 2025 found no comparable signal. Two 2025 papers combine imaging tests with millions of orbital simulations and conclude a real planet remains plausible, though not proven: if real, it would be a gas giant ~90–150 Earth masses orbiting around 1–2 AU with a high eccentricity, and could have slipped behind Webb’s coronagraphic blind spots between observations. Confirmation will require a future recovery of the signal or independent measurements; for now the evidence is intriguing but not conclusive.
