Parsec
| Parsec | |
|---|---|
 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). | |
| General information | |
| Unit system | astronomical units |
| Unit of | length |
| Symbol | pc |
| Conversions | |
| 1 pc in ... | ... is equal to ... |
| SI units | 3.0857×1016 m |
| imperial & US units | 1.9174×1013 mi |
| other astronomical | 2.0626×105 AU |
| units | 3.26156 ly |
A parsec 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.
