ephemeris second
Also found in: Dictionary.
ephemeris second
See ephemeris time.Collins Dictionary of Astronomy © Market House Books Ltd, 2006
ephemeris second
[ə′fem·ə·rəs ′sek·ənd] (astronomy)
The fundamental unit of time of the International System of Units from 1960 until 1968, equal to 1/31556925.9747 of the tropical year defined by the mean motion of the sun in longitude at the epoch 1900 January 0 day 12 hours.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
Copyright © 2003-2025 Farlex, Inc
Disclaimer
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.