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parsec (pc)




parsec
An astronomical unit of length, equal to the distance at which the radius of the Earth's orbit subtends an angle of one arcsecond. The name is a contraction of "parallax-second."

1 parsec = 3.259 light-years = 206,265 AU = 30.83 trillion km = 19.16 trillion miles.

The parsec is generally used by astronomers in preference to the light-year. For larger distances, the kiloparsec (kpc) = 1,000 pc or megaparsec (Mpc) = 1,000,000 pc are used.


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