Alpha Centauri A is a sun-like star about 4.3 light-years away from Earth. The latest research shows that it may have a huge planet. This candidate planet is located in the habitable zone of the star and may contain liquid water, but because it may be a gas giant planet, the possibility of harboring life is low. Relevant research has been submitted to Astrophysical Journal Letters.
Alpha Centauri A and its companion star Alpha Centauri B form a binary star system, and the red dwarf star Proxima Centauri orbits them. Currently, Proxima Centauri is the only star in the three-star system confirmed to have planets. Nanmen 2A has become an important target for planetary search because of its proximity to the Earth. However, its strong light and interference from companion stars make detection extremely difficult.
A research team from the California Institute of Technology in the United States used the infrared observation capabilities of the James Webb Space Telescope (JWST) and combined it with a coronagraph to block the star's light and successfully captured the signal of the candidate planet. Data show that the planet orbits at about twice the distance between the Sun and Earth, has a mass similar to Saturn, is close to Jupiter in size, and moves in an elliptical orbit.
If confirmed, the gas giant's gravity could perturb the habitable zone, affecting the existence of Earth-like planets. Although two follow-up observations in 2025 failed to capture the object, computer simulations suggest it may be temporarily undetectable due to its orbital position. The research team plans to observe again in August 2026 to verify its existence.
Although this discovery still needs further confirmation, it marks a major advancement in exoplanet detection technology. If finally confirmed, this will be the first exoplanet in the Milky Way galaxy located in the habitable zone of a sun-like star, providing important clues to the exploration of life in the universe.