From English apo- (prefix meaning ‘away from, separate’) + Ancient Greek ᾰ̓́στρον (ástron, “fixed star”), modelled after aphelion. Ἄ̆στρον (Ástron) is derived from ᾰ̓στήρ (astḗr, “celestial body (including a star, planet, meteor, etc.)”) (ultimately from Proto-Indo-European *h₂eHs- (“to burn; to glow”)) + -ον (-on, suffix forming nominative, accusative and vocative singular nouns).
- (Received Pronunciation) IPA(key): /æˈpæstɹ(ə)n/
Audio (RP) (file)
- (General American) IPA(key): /æˈpæstɹən/, [ə-]
- Hyphenation: ap‧as‧tron
apastron (plural apastrons)
- (astronomy) The point of greatest separation between a celestial object and the star which it orbits.
- Antonym: periastron