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The '''Sun''' is the star at the center of the [[solar system]], and it accounts for over 99% of the mass of the solar system. By mass, it is composed of 72% hydrogen, 26% helium and 2% trace elements of oxygen, carbon, neon, nitrogen, magnesium, iron, and silicon.<ref>[http://www.nasa.gov/worldbook/sun_worldbook.html World Book Encyclopedia @ NASA]</ref> The eight planets, including Earth, orbit the sun, as do countless other small objects.  

The '''Sun''' is a type G2V star; it is the star at the center of the solar system, and it accounts for over 99% of the mass of the solar system. By mass, it is composed of 72% hydrogen, 26% helium and 2% trace elements of oxygen, carbon, neon, nitrogen, magnesium, iron, and silicon.<ref>[http://www.nasa.gov/worldbook/sun_worldbook.html World Book Encyclopedia @ NASA]</ref> The eight planets, including Earth, orbit the sun, as do countless other small objects.  

It provides the [[Earth]] with light and heat.  

It provides the [[Earth]] with light and heat.