Parsec Parsec The parsec (symbol: pc) is a unit of length used to measure large distances to astronomical objects outside the Solar System. A parsec is defined as the distance at which one astronomical unit subtends an angle of one arcsecond, which corresponds to astronomical units. One parsec is equal to about 3.26 light-years (30 trillion km or 19 trillion miles) in length. The nearest star, Proxima Centauri, is about from the Sun. Most of the stars visible to the unaided eye in the night sky are within 500 parsecs of the Sun. The parsec unit was probably first suggested in
British Champions Long Distance Cup British Champions Long Distance Cup The British Champions Long Distance Cup is a Group 2 flat horse race in Great Britain open to thoroughbreds aged three years or older. It is run at Ascot over a distance of 1 mile 7 furlongs and 209 yards (3,209 metres), and it is scheduled to take place as part of British Champions Day each year in October. The event was originally held at Newmarket under the title Jockey Club Cup. It was established in 1873, and was initially contested over 2¼ miles. The distance of the race was shortened to 1½ miles in