Meaning

(astronomy) The point in the elliptical orbit of a comet, planet, etc., where it is nearest to the Sun..

Definitions by Sense

1. (astronomy) The point in the elliptical orbit of a comet, planet, etc., where it is nearest to the Sun.
2. (figurative) The highest point or state; the peak, zenith.

Example Sentences

The æquation of the Earth encreaſeth from her Aphelion, until ſhe come to the point where it's greateſt, and from thence it again decreaſeth till ſhe come to her Perihelion, or oppoſite Auge: in like manner it increaſeth from her Perihelion to the point where it's greateſt, and afterwards decreaſeth till ſhe come againe to the Auge or Aphelion, [...]

They [the best astronomers of this age] all agree that the Planets turn in ſo many Ellipſes, of which the Sun is the focus; the reaſon of it is, that they are obſerved to be in ſome points called Perihelia, nearer to the Sun, and, in the oppoſite points call'd Aphelia, farther from it; which could not be, if they mov'd in a perfect circle.

[I]f Comets were obſerv'd to have to Atmoſphere after their return from the Regions beyond Saturn, before they arrived at their Perihelia again, then indeed this reaſoning were unavoidable; but ſeeing the contrary is evident from Aſtronomical Obſervations, it cannot affect his [William Whiston's] Hypotheſis.

The base of the system is that all planets, comets and satellites go through a reversed change of motion, volume, distance and density at their perihelions and aphelions, each orbital revolution: this being effected through reciprocating electric currents or lines that exist and undulate between the planetary bodies, with which currents are used to carry on these planetary changes. These changes continue from perihelion to aphelion, and from aphelion to perihelion again, and are in proportion to the amount of ellipticity in their orbits—the greater the ellipticity the greater the changes.

This rotational motion could have the axis of minimum moments of inertia nearly aligned with the Sun–Mercury radius vector at every perihelion passage.

In this case, the rate of advance of the perihelia of their elliptical orbits provides important information about the masses of the neutron stars as well as providing very sensitive tests of general relativity itself.

The longitude of the comet is not usually specified at a particular epoch. Rather, the epoch is given when the comet is at perihelion, the point of its closest approach to the Sun. [...] Note that, as in the case of the planetary elements, we have specified ϖ, the longitude of the perihelion.

[T]he magnificence of his compliment had quite shaken the general's [Ulysses S. Grant's] modesty, and that he could only say that France must come to the perihelion of her glory under such rulers as Grevy [i.e., Jules Grévy].

Word Forms

• perihelia
• perihelions

Synonyms for perihelion

Antonyms for perihelion

Related Words

When Should You Use Perihelion?

Use perihelion when its meaning, tone and grammar fit the full sentence. A synonym is not always a direct replacement.

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