Which celestial movement is associated with the Mean Sun?

The Mean Sun is a theoretical concept used to provide a consistent point of reference for timekeeping. This imaginary sun moves along the celestial equator at a uniform speed, which allows it to provide a stable measure of time throughout the year. This constant speed simplifies the calculations for time zones and daily activities, as it behaves in a predictable manner.

By moving at this consistent pace, the Mean Sun allows for the establishment of mean solar time, which averages out the variations caused by the Earth's elliptical orbit and axial tilt. This is critical for maintaining a standardized time across different regions of the world, contrasting with the variations of the actual sun's position in the sky due to other celestial movements.

In this context, while the other options discuss different aspects of celestial motion, they do not align with the characteristics of the Mean Sun's movement, which is defined by its predictable, constant speed.