View source for Parsec

{{Infobox unit
| name = Parsec
| image = Stellarparallax parsec1.svg
| caption = A parsec is the distance from the [[Sun]] to an [[astronomical object]] which has a [[parallax]] angle of one [[arcsecond]]. (the diagram is not to scale).
| standard = astronomical units
| quantity = length
| symbol = pc
| units1   = [[International System of Units|SI units]]
| inunits1 = {{val|3.0857|e=16|ul=m}}
| units2   = [[Imperial units|imperial]] & [[United States customary units|US]] units
| inunits2 = {{val|1.9174|e=13|ul=mi}}
| units3   = other astronomical
| inunits3 = {{val|2.0626|e=5|ul=AU}}
| units4   = &nbsp;&nbsp;&nbsp;units
| inunits4 = {{val|3.26156}}&nbsp;[[light-year|ly]]
}}

The '''parsec''' (symbol: '''pc''') is a unit of distance used in [[astronomy]]. It is the distance that light travels in 3.26 years, or just under 31 trillion kilometres (about 19 trillion miles). 

This is from the [[definition]]: a parsec is the distance from the Sun to an object which has a [[parallax]] [[angle]] of one [[arcsecond]]. The technique used in the calculation is [[trigonometry]]. 

It takes 3.26 years for the light to come from a parsec away.

== Parsec Media ==
<gallery widths='160px' heights='100%' mode='traditional' caption=''>
File:ParallaxV2.svg|Stellar parallax motion from annual parallax

File:Parsec (1).svg|Diagram of parsec.

File:M87 jet.jpg|As observed by the [[Hubble Space Telescope]], the [[astrophysical jet]] erupting from the [[active galactic nucleus]] of [[Messier 87|M87]] [[subtends]] {{val|20|u=arcsecond}} and is thought to be {{convert|1.5|kpc|ly|lk=out|sigfig=4}} long (the jet is somewhat foreshortened from Earth's perspective).
</gallery>
== Related pages ==
*[[Astrometry]]

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[[Category:Astronomical distances]]
[[Category:Units of length]]