apastron

Meanings

1. The point of greatest separation between a celestial object and the star which it orbits.

Etymology

From English ap- (prefix meaning ‘away from, separate’) + Ancient Greek ᾰ̓́στρον (ắstron, “fixed star”), modelled after aphelion. Ἄ̆στρον (Á̆stron) is derived from ᾰ̓στήρ (ăstḗr, “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).