an imaginary sun moving uniformly in the celestial equator and taking the same time to make its annual circuit as the true sun does in the ecliptic.
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Words nearby mean sun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020
British Dictionary definitions for mean sun
an imaginary sun moving along the celestial equator at a constant rate and completing its annual course in the same time as the sun takes to move round the ecliptic at a varying rate. It is used in the measurement of mean solar time
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for mean sun
A hypothetical Sun defined as moving at a uniform rate along the celestial equator at the mean speed with which the real Sun apparently moves along the ecliptic, used in computing the mean solar day.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.