Proxima Centauri b (also known as Proxima b) is a confirmed exoplanet orbiting a red dwarf Proxima Centauri in the Alpha Centauri system, 4.2 light years away. It was discovered on August 24, 2016. It has a mass of 1.27 Earths (Radius: 1.1 Earths). It takes 11.2 days to orbit its star. It has an ESI of 1987 0.87, just below Kepler-438b (1988 0.88).