parsec: meaning, definition, pronunciation and examples
C2Technical, Scientific, Science Fiction
Quick answer
What does “parsec” mean?
A unit of astronomical distance equal to about 3.
Audio
Pronunciation
Definition
Meaning and Definition
A unit of astronomical distance equal to about 3.26 light-years, defined as the distance at which one astronomical unit subtends an angle of one second of arc.
While strictly an astronomical unit, 'parsec' has entered popular culture through science fiction, where it is sometimes used vaguely to convey vast interstellar distance and can be misused as a unit of time or speed.
Dialectal Variation
British vs American Usage
Differences
No significant difference in definition or use; it is an international scientific term.
Connotations
Identical connotations in scientific contexts. In popular culture, may be recognized from 'Star Wars' where it was famously (and controversially) used as a measure of a ship's speed capability ('the Kessel Run in less than twelve parsecs').
Frequency
Equally low frequency in both varieties; primarily used in astronomy, astrophysics, and related sci-fi media.
Grammar
How to Use “parsec” in a Sentence
[Number] + parsec(s) + [optional prepositional phrase (e.g., from Earth)]measured in + parsecsVocabulary
Collocations
Examples
Examples of “parsec” in a Sentence
adjective
British English
- parsec-scale structures
American English
- parsec-length baseline
Usage
Meaning in Context
Business
Virtually never used.
Academic
Used in astronomy, astrophysics, and cosmology papers and textbooks.
Everyday
Extremely rare; might be used in sci-fi discussions or trivia.
Technical
Standard unit for expressing distances to stars and galaxies within and beyond the Milky Way.
Vocabulary
Synonyms of “parsec”
Vocabulary
Antonyms of “parsec”
Watch out
Common Mistakes When Using “parsec”
- Using 'parsec' as a unit of time (e.g., 'It took three parsecs').
- Using 'parsec' as a unit of speed (the famous 'Star Wars' mistake).
- Confusing it with 'light-year' without understanding the different definitions (parsec is based on parallax; light-year is based on light travel).
FAQ
Frequently Asked Questions
Yes, one parsec is approximately 3.26 light-years.
Because Han Solo uses it to describe the speed of his ship ('made the Kessel Run in less than twelve parsecs'), but a parsec is a unit of distance, not time or speed. Fans have since created complex lore to explain this as a shortcut through a dangerous route.
Primarily in professional astronomy and astrophysics to express distances to stars, within our galaxy, and between galaxies. It is more convenient than light-years for calculations involving stellar parallax.
Kiloparsec (kpc) is 1,000 parsecs, used for distances within a galaxy. Megaparsec (Mpc) is 1,000,000 parsecs, used for distances between galaxies.
A unit of astronomical distance equal to about 3.
Parsec is usually technical, scientific, science fiction in register.
Parsec: in British English it is pronounced /ˈpɑː.sɛk/, and in American English it is pronounced /ˈpɑːr.sɛk/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “It's not parsecs away (humorous: it's not that far)”
Learning
Memory Aids
Mnemonic
Parsec = PARallax of one SECond of arc. Think of the Earth's orbit (1 AU) creating a tiny angle (1 second) – that's a parsec away.
Conceptual Metaphor
DISTANCE IS MEASURED SPAN (a specific, immense span defined by geometry). In sci-fi, it can be metaphorically used for TIME IS DISTANCE ('a journey of a thousand parsecs').
Practice
Quiz
What does one parsec represent?