Množina: parsecs

A unit of astronomical length based on the distance from Earth at which stellar parallax is 1 second of arc; equivalent to 3.262 light years; SYN. secpar.
Astronomical measure of distance, approximately equivalent to 19.5 billion miles.
In astronomy, a unit (symbol pc) used for distances to stars and galaxies. One parsec is equal to 3.2616 light-years, 2.063 x 105 astronomical units, and 3.086 x 1013 km.
It is the distance at which a star would have a parallax (apparent shift in position) of one second of arc when viewed from two points the same distance apart as the Earth's distance from the Sun; or the distance at which one astronomical unit subtends an angle of one second of arc.