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 eccentricity of their orbit approaches in form that of Faye’s comet, which travels round the Sun; consequently the stars, when at apastron, are twice their periastron distance.

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

All went well, there were no incidents, no vessels disturbed him; though had the two components of the binary been at periastron, it would have simplified the work with the position micrometer.

From Next Door, Next World by Locke, Robert Donald

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

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