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Määritelmät

Substantiivi

1. The time that it takes for the Sun to return to the same position along the ecliptic, as viewed from the Earth, especially, completing a full cycle of seasons.
2. (in particular) A vernal equinox year; the time between two successive vernal equinoxes.
3. (by extension) The time it takes for any astronomical object (such as a planet, dwarf planet, small Solar System body, or comet) in direct orbit around a star (such as the Sun) to make one revolution around the star, taking into account orbital precession.