periastron
|per-i-as-tron|
🇺🇸
/ˌpɛr.iˈæstrɑn/
🇬🇧
/ˌpɛrɪˈæstrɒn/
closest point to a star
Etymology
'periastron' originates from Greek elements, specifically from 'peri-' and 'astron', where 'peri-' meant 'around, near' and 'astron' meant 'star'.
'periastron' was formed in modern astronomical usage by combining the Greek elements 'peri-' + 'astron', modeled on related astronomical terms such as 'perihelion' and 'apastron' to denote the closest approach to a star.
Initially a compound literally meaning 'near star', it evolved into the technical astronomical term for 'the point of closest approach in an orbit (especially in binary-star contexts)'.
Meanings by Part of Speech
Noun 1
the point in the orbit of one body (typically in a binary star system) at which it is nearest to the other body; the counterpart of apastron.
The two stars show increased activity when they pass through periastron.
Synonyms
Antonyms
Last updated: 2025/12/02 10:34