Parsec but in globular clusters the stellar density could be from 100 to 1000 per cubic 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
Pace (unit) it was standardized as the distance of two steps (') or five Roman feet ('), about . There were 1000 paces in the Roman mile, which was named after that distance as the ' or '. The Byzantine pace (, "bḗma") was an adaption of the Roman step, a distance of 2½ Greek feet. The double pace (, "bḗma diploûn"), meanwhile, was similar to the Roman unit, comprising 5 Greek feet. The Welsh pace () was reckoned as 3 Welsh feet of 9 inches and thus may be seen as similar to the English yard: 3 paces made up a