sidereal month

plural sidereal months

Definition of sidereal month

: the mean time of the moon's revolution in its orbit with reference to a star's position : 27 days, 7 hours, 43 minutes, 11.5 seconds of mean time The Moon rotates on its axis once every 27.32166 days. This is the sidereal month and corresponds to the time taken for the average period of revolution of the Moon about the Earth.— Stuart Ross Taylor

First Known Use of sidereal month

1833, in the meaning defined above

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The first known use of sidereal month was in 1833

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Cite this Entry

“Sidereal month.” Dictionary, Merriam-Webster, Accessed 12 Aug. 2020.

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