A parsec is a unit of distance used in astronomy and astrophysics to measure the large distances to astronomical objects outside the Solar System
. It is approximately equal to 3.26 light-years
. The term "parsec" is a combination of "parallax" and "arcsecond"
. Parsec is the distance at which the radius of Earth's orbit subtends an angle of one second of arc
. Some key points about parsecs include:
- One parsec is equal to 3.26 light-years, which is equivalent to 3.09 × 10^13 km (1.92 × 10^13 miles)
- The distance to the nearest star, Proxima Centauri, is 1.30 parsecs
- In the Milky Way Galaxy, distances to remote stars are measured in terms of kiloparsecs (1 kiloparsec = 1,000 parsecs)
- The Sun is at a distance of 8.3 kiloparsecs from the center of the Milky Way system
- Parsecs are used for shorter distances within the Milky Way, while multiples of parsecs are required for larger scales in the universe, including megaparsecs (1 megaparsec = 1,000,000 parsecs) for objects like the Andromeda Galaxy
The International Astronomical Union recommends the use of parsecs over light- years in scientific publications, although light-years are still commonly used in popular science texts and common usage
