equinoctial circle
- noun
- /ˌɛkwɪˈnɒkʃəl ˈsɜrkl/
- Specialized
- The path of the Sun crosses the equinoctial circle at the equinoxes.
Examples
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Ancient astronomers used the equinoctial circle as a reference when charting the stars.
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The equinoctial circle divides the sky into northern and southern hemispheres.
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The equinoctial circle divides the sky into northern and southern hemispheres.
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Can you explain the significance of the equinoctial circle?
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Ancient astronomers used the equinoctial circle as a reference when charting the stars.
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The equinoctial circle divides the sky into northern and southern hemispheres.
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The path of the Sun crosses the equinoctial circle at the equinoxes.
Synonyms
An imaginary circle around the sky above Earth's equator
A circle in the sky halfway between the sky's north and south poles
An imaginary line in the sky that matches Earth's equator and divides the sky into north and south
Surface Forms
Morphology
The term is compositionally built from 'equinoctial' (relating to the equinox or celestial equator) + 'circle' (a round line), so its meaning as a circle associated with the equinox/celestial equator is directly derivable. It is a technical astronomical label but the semantic relation is transparent and paralleled in other languages, so a learner who knows both constituents would infer the meaning.
Etymology
Equinoctial circle comes from old Latin words that mean 'equal' and 'night', and its parts are equinoctial and circle. It names the large circle in the sky that lines up with Earth's equator. At the equinoxes the Sun crosses this circle and day and night are nearly equal, so the name links the circle to 'equal night'.