parsec (symbol pc)

A unit of distance used in professional astronomy. It is defined as the distance at which an object would have an annual parallax of one arc second. It is equivalent to 3.0857 × 1013 kilometres, 3.2616 light years or 206,265 astronomical units. Multiples in common use are the kiloparsec (kpc, 1,000 parsecs) and the megaparsec (Mpc, 1,000,000 parsecs).