Fastest moving star in the sky

Barnard's star moves 10357.704 mas/yr across the sky. The figure was obtained by the high-precision Hipparcos satellite. This movement, called proper motion, means that Barnard's star moves a distance in the sky equivalent to the size of the full Moon in 170 years. mas/yr = milliarcseconds per year. There are 60 arcseconds to an arcminute and 60 arcminutes in a degree. The full Moon is half a degree across in the sky. All the stars in the Milky Way spiral galaxy slowly orbit the galactic centre. The Sun, at a distance of around 30,000 light years from the centre takes around 230 million years to go around once. Different stars orbit the centre at different velocities. This means that, over time, the relative positions of the stars in the sky can change. Barnard's star is the second-nearest star to our Solar System (5.97 light years). It has an apparent magnitude of 9.56, far too faint to be seen with the naked eye, as it is a faint red dwarf star. Barnard's star is actually approaching the Solar System at around 111 km per second (69 miles per sec) and will come as close as 3.85 light years by the year 11,800 CE. Barnard's star is part of the constellation of Ophiuchus Barnard's star was discoverd in 1916 by E.E. Barnard at the Yerkes Observatory. He realised its large proper motion by comparing photographs taken in 1894 and 1916, and then tracing the star back to photographic plates taken in 1888.