Most stars visible to the naked eye are within a few hundred parsecs of the Sun, with the most distant at a few thousand parsecs, and the Andromeda galaxy at over 700 thousand parsecs. The nearest star, Proxima Centauri, is about 1.3 parsecs (4.2 light-years) from the Sun: from that distance, the gap between the Earth and the Sun spans slightly less than 1 / 60 of 1 / 60 of one degree of view. The parsec unit is obtained by the use of parallax and trigonometry, and is defined as the distance at which 1 AU subtends an angle of one arcsecond ( 1 / 3600 of a degree). 30.9 trillion kilometres (19.2 trillion miles). The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to 3.26 light-years or 206,265 astronomical units (AU), i.e. A parsec is the distance from the Sun to an astronomical object that has a parallax angle of one arcsecond (not to scale)
