Barnard's Star, also known occasionally as Barnard's "Runaway" Star, is a very low-mass red dwarf star approximately six light-years away from Earth in the constellation of Ophiuchus (the Snake-holder). In 1916, the American astronomer E.E. Barnard measured its proper motion as 10.3 arcseconds per year, which remains the largest-known proper motion of any star relative to the Sun. At a distance of about 1.8 parsecs from the Solar System, or just under six light-years, Barnard's Star is the nearest known star in the constellation Ophiuchus, and the fourth-closest known individual star to the Sun, after the three components of the Alpha Centauri system. Despite its proximity, Barnard's Star, at a dim apparent magnitude of about nine, is not visible with the unaided eye; however, it is much brighter in infrared light than it is in visible light.
Barnard's Star has been the subject of much study, and it has probably received more attention from astronomers than any other class M dwarf star due to its proximity and favorable location for observation near the celestial equator. Historically, research on Barnard's Star has focused on measuring its stellar characteristics, its astrometry, and also refining the limits of possible extrasolar planets. Although Barnard's Star is an ancient star, some observations suggest that it still experiences star flare events.
Barnard's Star has also been the subject of some controversy. For a decade, from the early 1960s to the early 1970s, Peter van de Kamp claimed that there was a gas giant planet (or planets) in orbit around it. While the presence of small terrestrial planets around the star remains a possibility, Van de Kamp's specific claims of large gas giant planets were refuted in the mid 1970s.
Barnard's Star is also notable as the target for Project Daedalus, a study on the possibility of fast, unmanned travel to nearby star systems.
Barnard's Star in Space Opera settings:
- Hyperion? (1989–1997), novels by Dan Simmons?. Barnard's Star had a farm-like habitable planet called Barnard's World? which was the homeworld of Rachel and Sol Weintraub, the latter being one of the seven Hyperion pilgrims depicted in the first two books.
- Frontier?: Elite II and Frontier: First Encounters, computer games. Barnard's Star is an important Federation? industrial system with heavy mining and refining industry close to Earth and the other Core Systems. It proved to be the ideal beginners trading place—no pirates and high profits, exporting robots or computers to Sol and importing Luxury Goods from there could make you a millionaire in no time at all.
- In GURPS Traveller?: Interstellar Wars, Barnard's Star is the first interstellar destination for Terran-made jump ships, who found a colony of humans from the Vilani Imperium on arrival.
- DarkSpace? presents the star with its own stellar system.
- In C. J. Cherryh's Alliance-Union future history, Barnard's Star is the site of Alpha Station, the first destination out from Sol on the "Great Circle" chain of space stations that terminates at Pell Station in the Tau Ceti system.
- In Known Space the system has a space station, Barnard's Starbase that was attacked by Kzin in 2449.
- Escape Velocity game by Ambrosia Software. System of New Sahara planet.