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Glite Dictionary
parsec

parsec

8 9.9
A unit used to measure large distances in space equal to about 3.26 light years
  • noun
  • /ˈpɑrˌsɛk/
  • Specialized
: parsec
  • The nearest star system, Proxima Centauri, is about 1.3 parsecs away from us.
  • parsec is 3.26
  • parsec (3.26 light-years)
  • one parsec

Examples

  • When astronomers measure distances in space, they often use parsecs instead of light years.

  • But a parsec is a measure of distance, not time.

    Happy Death Day 2U (2019)

  • Um, isn't a parsec a unit of distance, not time?

    Life in a Day (2011)

  • A parsec is 3.26 light-years.

    Academic text (2005)

  • In the center of a typical globular cluster, a cube one parsec on a side contains about 20,000 stars.

    Academic text (1990)

  • Zorkfox: A parsec is defined to be the distance at which 1 astronomical unit (distance from Earth to the Sun) is 1 arcsecond in angular size, so it's not a coincidence at all that the two numbers are the same.

    Blog text (16)

  • A parsec is a "parallax arcsecond," which means that "something at this distance will appear to shift by a parallax angle of one arcsecond when we observe it from the two sides of Earth's orbit."

    Blog text (16)

  • A star with a parallax angle of 1 arcsecond is defined to be 1 parsec from Earth.

Synonyms

secpar
vsparsec
  • Specialized
9.9

A unit for measuring distances to stars that equals about 3.26 light-years

is the same unit but uses a slightly different rounded value and phrasing

How Far

megaparsec
  • Specialized
1 9.9
kiloparsec
  • Specialized
1 9.9
parsec
  • Specialized
8 9.9
light-year
  • Specialized
62 4.9

Surface Forms

parsec singular
parsecs plural

Morphology

parsec = parallax + second (opaque) = parallax + second

Although formed from 'parallax' + 'second' (of arc), the resulting technical unit denotes a specific astronomical distance and is unlikely to be inferred by an average learner from the component words.

Etymology

Parsec is a short form made from parallax and arcsecond: parallax means an 'apparent shift' of a star when we move, and arcsecond means a 'very small angle'. So a parsec is the distance at which a star's parallax is one arcsecond, which is why astronomers use parsecs to measure the huge distances between stars.