galactic coordinate system(redirected from Galactic co-ordinate)
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galactic coordinate system
A celestial coordinate system in which an object's position on the celestial sphere is defined relative to the plane of the Milky Way galaxy and the two poles formed by a line through the center of the galaxy perpendicular to the plane.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.