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sidereal year
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Study the different ways of defining a year - a tropical year, a sidereal year, and the anomalistic year
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sidereal year

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Study the different ways of defining a year - a tropical year, a sidereal year, and the anomalistic year
Study the different ways of defining a year - a tropical year, a sidereal year, and the anomalistic year Learn about the different definitions of a year: a tropical year, a sidereal year, and an anomalistic year.

A sidereal year is the time it takes for Earth to complete one orbit around the Sun, measured in relation to the fixed stars. This duration is approximately 365 days, 6 hours, 9 minutes, and 9.5 seconds of mean time.1

The sidereal year is slightly longer than the solar year (also known as the tropical year). The solar year is the time between two successive vernal equinoxes and is about 365 days, 5 hours, 48 minutes, and 46 seconds. This difference is due to the precession of the equinoxes, which is a slow wobble in Earth's rotation.2

A sidereal day, measured by the passage of stars across the meridian, is shorter than an apparent solar day, which is measured by the Sun's passage across the meridian.3

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3 Britannica Sources
  1. sidereal year
  2. year
  3. time - Variations in the Earth’s rotation rate

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