Barnard's Star

Barnard's Star ( /ˈbɑrnərd/), also known occasionally as Barnard's "Runaway" Star, is a very low-mass red dwarf star about six light-years away from Earth in the constellation of Ophiuchus, the Snake-holder. Barnard's Star is 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 the infrared than it is in visible light. The star is named for American astronomer E.E. Barnard. He was not the first to observe the star, but in 1916 he measured its proper motion as 10.3 arcseconds per year, which remains the largest-known proper motion of any star relative to the Sun.

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.