Parsec
Related Category: Astronomy: General
(pär´sĕc) [
parallax +
second], in astronomy, basic unit of length for measuring interstellar and intergalactic distances, equal to 206,265 times the distance from the earth to the sun, 3.26 light-years, or 3.08 × 10
13 km (about 19 million million mi). The distance in parsecs of an object from the earth is the reciprocal of the
parallax of the object. The nearest star, Proxima Centauri, has a parallax of 0.763´´ of arc and a distance of about 1.31 parsecs.
