periastron

noun

peri·​as·​tron

¦perē¦astrən,

-ˌsträn

plural periastra

-strə

: the point in the orbit of a star or other celestial body where it is nearest to the primary star with reference to which it is revolving

the periastron of a comet

compare apastron

Word History

Etymology

New Latin, from peri- + Greek astron star

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