Cosmic Hide-and-Seek: Webb Spots a Planet Near a Neighboring Star ⚡ экспресс
Coronagraphic observations of α Centauri A with JWST/MIRI across three epochs (2024-2025) achieved sensitivity to detect planets with T~225–250 K (1–1.2 R_Jup) at 1–2″ and exozodiacal dust brighter than 5–8 zodis. The non-detection of dust sets a record upper limit of a few zodis, >10 times stricter than previous measurements. In August 2024, a point source S1 (3.5 mJy, 15.5 µm, 1.5″) was registered, ruled out as background/foreground, but unconfirmed due to limited data. In subsequent epochs, S1 was not detected. Comparison with candidate C1 (VLT/NEAR, 2019) indicates a 52% probability of missing it due to orbital motion; dynamical modeling of non-detections gives orbits with a period of 2–3 years, e~0.4, and mutual inclination of ~50° or 130° to the α Cen AB plane. Photometry and orbital properties yield a temperature of ~225 K, radius ~1–1.1 R_Jup, and mass of 90–150 M_Earth, consistent with RV limits.
The nearest Sun-like star, Alpha Centauri A, shines just four light-years away. The James Webb Space Telescope stared at it, blocking the star with a coronagraph — like holding a hand up to spot the Sun’s satellites. This is how it searched for planets and dust. It found almost no dust: remarkably clean, as if someone swept away the cosmic debris. But in August 2024, a dot called S1 appeared: an object the size of Jupiter, but surprisingly not icy — around –20°C (based on brightness). Then it vanished. Probably, its orbit is so stretched that it hides behind the star every 2–3 years, plunging from cold to warmth. If S1 is the same planet spotted in 2019 as C1, this is one of the lightest worlds directly imaged around a Sun-like star: 90–150 Earth masses.
🎯 The same system has Proxima b — an Earth-sized planet where a year lasts just 11 days.
🎬 In ‘Avatar,’ the planet Polyphemus and its moon Pandora orbit Alpha Centauri A — our searches make that world a little more real.