Barnard's star, star with the largest observed proper motion proper motion, in astronomy, apparent movement of a star on the celestial sphere , usually measured as seconds of arc per year; it is due both to the actual relative motions of the sun and the star through space. Proper motion reflects only transverse motion, i.e.
..... Click the link for more information. (rate of motion across the sky with respect to other stars); located in the constellation Ophiuchus. The star's large proper motion, 10.28" per year (or half the moon's apparent diameter in a century), is due in part to the fact that it is the second-nearest star, being at a distance of 5.98 light-years. Barnard's star was discovered in 1916 by E. E. Barnard, an observer known also for his discoveries of 16 comets. It is a faint red dwarf star, apparent magnitude magnitude, in astronomy, measure of the brightness of a star or other celestial object. The stars cataloged by Ptolemy (2d cent. A.D.), all visible with the unaided eye, were ranked on a brightness scale such that the brightest stars were of 1st magnitude and the
..... Click the link for more information. 9.5, of spectral class spectral class, in astronomy, a classification of the stars by their spectrum and luminosity . In 1885, E. C. Pickering began the first extensive attempt to classify the stars spectroscopically.
..... Click the link for more information. M5, lying near the bottom of the main sequence in the Hertzsprung-Russell diagram Hertzsprung-Russell diagram [for Ejnar Hertzsprung and H. N. Russell ], graph showing the luminosity of a star as a function of its surface temperature. The luminosity, or absolute magnitude , increases upwards on the vertical axis; the temperature (or some
..... Click the link for more information. . Slight oscillations in its motion indicate that it has at least one unseen companion.

Barnard's star

Star about six light-years away from the Sun, next nearest the Sun after the Alpha Centauri system, in the constellation Ophiuchus. Named for Edward Emerson Barnard (b. 1857—d. 1923), who discovered it in 1916, it has the largest proper motion of any known star. It is gradually nearing the solar system. The star attracted astronomers' attention in the 1960s when its proper motion was claimed to show periodic deviations attributed to the gravitational pull of two planets (see planets of other stars). The deviations were later proved to be artifacts of measurement.