sun

sun

The Sun is a it was born in the later stages of the and thus contains more elements heavier than hydrogen and helium ("in astronomical parlance) than older population II stars. Elements heavier than hydrogen and helium were formed in the of ancient and exploding stars, so the first generation of stars had to die before the universe could be enriched with these atoms. The oldest stars contain few metals, while stars born later have more. This high metallicity is thought to have been crucial to the Sun's developing a, because planets form from accretion of "metals"

The Sun is the Solar System's star, and by far its chief component. Its large mass (332,900 Earth masses) produces temperatures and densities in its great enough to sustain which releases enormous amounts of mostly into as peaking in the 400–to–700 nm band we call

The Sun is classified as a type G2 but this name is misleading as, compared to the majority of stars in Sun is rather large and bright. Stars are classified by the a graph which plots the brightness of stars with their surface Generally, hotter stars are brighter. Stars following this pattern are said to be on the nd the Sun lies right in the middle of it. However, stars brighter and hotter than the Sun are rare, while substantially dimmer and cooler stars, known as are common, making up 85 percent of the stars in the galaxy

It is believed that the Sun's position on the main sequence puts it in the "prime of life" for a star, in that it has not yet exhausted its store of hydrogen for nuclear fusion. The Sun is growing brighter; early in its history it was 70 percent as bright as it is today.