[ uh-pas-truh n, -tron ]
/ əˈpæs trən, -trɒn /

noun, plural ap·as·tra [uh-pas-truh] /əˈpæs trə/. Astronomy.

the point at which the stars of a binary system are farthest apart (opposed to periastron).

Origin of apastron

< New Latin < Greek ap- ap-2 + ástron star, constellation; on the model of apogee
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Science definitions for apastron


[ ə-păstrən ]

The point at which an object, such as a planet or comet, is farthest from the center of mass of the star it is orbiting. Compare periastron.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.