periastron

noun peri·as·tron \¦perē¦astrən, -ˌsträn\

Definition of periastron

plural

periastra

\-strə\
  1. :  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

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Origin and Etymology of periastron

New Latin, from peri- + Greek astron star — more at star


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