astronomical twilight

noun

Definition of astronomical twilight

: the period after sunset or before sunrise ending or beginning when the sun is about 18 degrees below the horizon

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Dictionary Entries Near astronomical twilight

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Cite this Entry

“Astronomical twilight.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/astronomical%20twilight. Accessed 27 Oct. 2021.

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