Anomalistic Year

The perihelion is the point of closest approach between a planet and the Sun. The time at which a planet reaches perihelion provides a convenient measurement of the duration of the orbit. The anomalistic year is defined as the time between successive perihelion passages.

The time period between two perihelion passages is the anomalistic year.

Using the Earth as an example:

Year Duration (days)
Tropical year 365.24219
Sidereal period 365.25636
Anomalistic year 365.25964

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