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
PC strand T 5224, American Standard ASTM A416, British standard BS 5896 and the Japanese standard JIS G3536, the Australian standard AS / NZS 4672, Brazilian standard NBR-7483 3, http://www.pcstrand.cn/f694801/What's-PC-STRAND.htm PC strand PC Strand, or prestressed concrete steel strand, is a twisted steel cable composed of 2, 3, 7 or 19 high strength steel wires and is stress-relieved (stabilized) for prestressed concrete or similar purposes. PC strand is classified according to the number of steel wires in a strand: 2 wire strand, 3 wire strand, 7 wire steel strand and 19 wire steel strand. It can be classified according to the surface