Alpha Centauri is the nearest star system to the Sun at 4.37 light-years, comprising a close binary of Sun-like Alpha Centauri A (G2V, 1.1 solar masses) and orange Alpha Centauri B (K1V, 0.9 solar masses). The pair orbits with a period of 79.9 years, an eccentricity of 0.52, and a semi-major axis of 23.4 AU — swinging between 11 and 36 AU separation. This scenario starts at apastron, when the stars are at their widest spacing, and models only the close A–B binary. In the full triple system, Proxima Centauri orbits roughly 15,000 AU away and hosts at least two confirmed exoplanets, including Proxima b in the habitable zone.