periastron

American  

[per-ee-as-truhn, -tron] / ˌpɛr iˈæs trən, -trɒn /

noun

Astronomy.

plural

periastra

1. the point at which the stars of a binary system are closest (apastron ).

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periastron British  

/ ˌpɛrɪˈæstrɒn /

noun

1. astronomy the point in the orbit of a body around a star when it is nearest to the star, esp applied to double-star systems

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periastron Scientific  

/ pĕr′ē-ăs′trən,-trŏn /

plural

periastra

1. The point at which an object, such as a planet or comet, is closest to the center of mass of the star it is orbiting.

2. Compare apastron

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Other Word Forms

• periastral adjective

Etymology

Origin of periastron

1850–55; < peri- + Greek ástron star; modeled on perihelion

Example Sentences

The pair travel in an orbit from fourteen to forty-two times the radius of the Earth’s orbit; so that when at apastron they are three times as distant from each other as when at periastron.

From The Astronomy of Milton's 'Paradise Lost' by Orchard, Thomas Nathaniel

At least, the periastron effects; there was another angle to it.

From Oomphel in the Sky by Piper, H. Beam

It seems that the government here knew all about the weather conditions they could expect at periastron, and had made plans for them.

From Oomphel in the Sky by Piper, H. Beam

There was a project to provide shelters for the periastron storms set up ten years ago.

From Oomphel in the Sky by Piper, H. Beam

The last periastron was ninety years ago, and we've only been here for sixty-odd; all we have is verbal accounts from memory from the natives, probably garbled and exaggerated.

From Oomphel in the Sky by Piper, H. Beam