The true orbital period of Earth around the Sun,defined as the time taken to complete one orbit with respect to the background stars,is one:
A) sidereal year.
B) Gregorian year.
C) tropical year.
D) solar day.

Question

Quizplus · Accepted Answer

The true orbital period of Earth around the Sun with respect to the background stars is defined as a sidereal year, which is the time taken by Earth to complete one orbit around the Sun with reference to the fixed stars. It is approximately 365.26 days long. A tropical year is the time taken by Earth to complete one orbit with reference to the vernal equinox and is approximately 20 minutes shorter than a sidereal year. A solar day is the time taken by Earth to complete one rotation around its own axis with reference to the Sun, and a Gregorian year is a calendar year with 365 days (and 366 days in a leap year).

The True Orbital Period of Earth Around the Sun,defined as the Time