Alpha Centauri

Alpha Centauri (α Cen / α Centauri, also known as Rigil Kentaurus), is the brightest star system in the southern constellation of Centaurus. Although it appears as a single point to the naked eye, Alpha Centauri is actually a system of three stars, one of which is the fourth brightest star in the night sky. Alpha Centauri is famous in the Southern Hemisphere as the outermost "pointer" to the Southern Cross, but it is too far south to be visible in most of the northern hemisphere. The two brightest components of the system are too close to be resolved as separate stars by the naked eye and so are perceived as a single source of light with a total visual magnitude of about −0.27 (brighter than the third brightest star in the night sky, Arcturus).

Alpha Centauri is the closest star system to our own solar system at 4.37 light-years distant (about 41.5 trillion km, 25.8 trillion miles or 277,600 AU). Proxima Centauri, usually regarded as part of the system, is the closest star at 4.22 light-years distant. Alpha Centauri's relative proximity makes it a logical choice as "first port of call" in speculative fiction about interstellar travel, which predicts eventual human exploration, and even the discovery and colonization of planetary systems. These themes are common to countless works of science fiction and video games.