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Light-year

The distance light travels in one standard or metric (Earth) year, viz. 9.46x10^{12} km. Standard unit of measurement. It is equal to 6.323x10^{4} astronomical units (AU) or 0.307 parsecs.

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**AU (Astronomical Unit)**- Text by M. Alan Kazlev

Astronomical Unit - the mean distance of the Earth to the Sun (SolSys), about 1.496 x 108 km (150 million km), 8.3 light minutes, 1.582x10^{-5}light years, or 4.847x10^{-6}parsecs. Standard interplanetary measurement.**Parsec**- Text by M. Alan Kazlev

Unit of distance at which a star would have a parallax of 1 second of arc from a planet of exactly 1 astronomical unit (AU) distance from its primary. One parsec is equal to 3.262 light-years, 2.063x10^{5}AU, or 3.085678 x10^{13}kilometers.**Year**

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Development Notes

Text by M. Alan Kazlev

Initially published on 03 December 2001.

Initially published on 03 December 2001.