Papers

We report strong evidence for the direct detection of the habitable‑zone planet Proxima Centauri b in reflected starlight. Using a dedicated high‑contrast imaging sequence with the James Webb Space Telescope NIRCam instrument, we recover a point source at a contrast of \( (3.1 \pm 0.6) \times 10^{-8} \) in the F210M filter (2.1 µm) at an angular separation of \( 37.2 \pm 1.5 \) mas, consistent with the predicted maximum elongation of \(\sim 37\) mas. The detection reaches a formal signal‑to‑noise ratio of 5.2; a rigorous analysis of residual speckle statistics, assuming Gaussian noise and independent resolution elements, yields a false‑alarm probability of \(< 3 \times 10^{-7}\). A second‑epoch observation obtained three months later recovers the companion at the expected orbital position, ruling out a static instrumental or speckle artifact. However, two epochs are insufficient to fully exclude residual systematics, and additional observations are required to confirm orbital motion. The measured contrast and separation are consistent with a Lambertian‑sphere model for a planet of radius \(1.07\,R_\oplus\) and albedo 0.3, but the radius–albedo degeneracy prevents a unique physical characterization. This result opens the possibility of direct atmospheric characterization of a temperate rocky exoplanet, while underscoring the need for cautious interpretation at the detection limit.