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optical binary

American

noun

Astronomy. a pair of stars that appear close together when observed from Earth, but which are not actually close in physical space.

optical binary Scientific

See under binary star

Other Word Forms

Noun Inflected Forms

optical binaries

plural

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.