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The Sun is the star at the center of the Solar System, holding the system together by its gravity. It constitutes about 99.8% of the mass of the system and is the main source of heat and light for the other bodies.

It is a yellow dwarf star. It is rather brighter, hotter and more massive than the average star in its vicinity, but not vastly so.

The Sun is made up of gas undergoing a nuclear fusion reaction in which hydrogen is converted to helium at very high temperatures and pressures.

The Sun rotates, but at a slower rate than earth. The outer part rotates at different speeds, depending how close to the equator or the poles one is observing. The inner core rotates at a consistent rate. A point 26 degrees from the equator on the surface takes 25.8 days to rotate. This arbitrary point was selected because it is where we see most sunspots.

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