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[per-uh-hee-lee-uh n, -heel-yuh n] /ˌpɛr əˈhi li ən, -ˈhil yən/
noun, plural perihelia
[per-uh-hee-lee-uh, -heel-yuh] /ˌpɛr əˈhi li ə, -ˈhil yə/ (Show IPA).
the point in the orbit of a planet or comet at which it is nearest to the sun.
Compare aphelion.
Origin of perihelion
1660-70; < Greek peri- peri- + hḗli(os) sun + -on neuter noun suffix, on the model of perigee; earlier in the New Latin form perihelium
Related forms
perihelial, perihelian, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the Web for perihelia
Historical Examples
  • The extremes of temperature at perihelia and aphelia to which comets are subjected did not bother him particularly.

    Astronomy David Todd
  • This tendency of the perihelia to crowd together in two opposite regions has been noticed by different writers.

    Comets and Meteors Daniel Kirkwood
  • The maximum occurs between 30 and 60, where thirty-five perihelia are found in 30 of longitude.

    The Asteroids Daniel Kirkwood
  • It is a remarkable fact, however, that the longitudes of their perihelia differ by almost exactly 180.

    The Asteroids Daniel Kirkwood
  • At the second, Encke's comet and all others with perihelia within Mercury's orbit would have shared a similar fate.

    The Asteroids Daniel Kirkwood
British Dictionary definitions for perihelia


noun (pl) -lia (-lɪə)
the point in its orbit when a planet or comet is nearest the sun Compare aphelion
Word Origin
C17: from New Latin perihēlium, from peri- + Greek hēlios sun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for perihelia



"point at which a celestial body is nearest the Sun," 1680s, coined in Modern Latin (perihelium) by Kepler (1596) from Latinizations of Greek peri "near" (see peri-) + helios "sun" (see sol). Subsequently re-Greeked.

Online Etymology Dictionary, © 2010 Douglas Harper
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perihelia in Science

The point at which an orbiting object, such as a planet or a comet, is closest to the Sun. Compare aphelion, perigee.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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