Proxima Centauri b Proxima Centauri b Proxima Centauri b (also called Proxima b or Alpha Centauri Cb) is an exoplanet orbiting in the habitable zone of the red dwarf star Proxima Centauri, which is the closest star to the Sun and part of a triple star system. It is located about 4.2 light-years (1.3 parsecs, 40 trillion km, or 25 trillion miles) from Earth in the constellation of Centaurus, making it the closest known exoplanet to the Solar System. Proxima Centauri b orbits the star at a distance of roughly with an orbital period of approximately 11.2 Earth days, and has an estimated
Pace (unit) it was standardized as the distance of two steps (') or five Roman feet ('), about . There were 1000 paces in the Roman mile, which was named after that distance as the ' or '. The Byzantine pace (, "bḗma") was an adaption of the Roman step, a distance of 2½ Greek feet. The double pace (, "bḗma diploûn"), meanwhile, was similar to the Roman unit, comprising 5 Greek feet. The Welsh pace () was reckoned as 3 Welsh feet of 9 inches and thus may be seen as similar to the English yard: 3 paces made up a