Tuesday, December 16, 2008
Sun
The Sun is the Solar System's parent star, and far and away its chief part. Its large mass gives it an center density high enough to maintain nuclear fusion, which releases huge amounts of energy, typically radiated into space as electromagnetic radiation such as visible light.
The Sun is classified as a moderately big yellow dwarf, but this name is deceptive as, compared to stars in our galaxy, the Sun is quite large and bright. Stars are classified by the Hertzsprung-Russell diagram, a graph which plots the intensity of stars against their surface temperatures. Usually, hotter stars are brighter. Stars following this pattern are said to be on the main series; the Sun lies right in the center of it. However, stars brighter and hotter than the Sun are rare, while stars dimmer and cooler are common.
The Sun is the Solar System's parent star, and far and away its chief part. Its large mass gives it an center density high enough to maintain nuclear fusion, which releases huge amounts of energy, typically radiated into space as electromagnetic radiation such as visible light.
The Sun is classified as a moderately big yellow dwarf, but this name is deceptive as, compared to stars in our galaxy, the Sun is quite large and bright. Stars are classified by the Hertzsprung-Russell diagram, a graph which plots the intensity of stars against their surface temperatures. Usually, hotter stars are brighter. Stars following this pattern are said to be on the main series; the Sun lies right in the center of it. However, stars brighter and hotter than the Sun are rare, while stars dimmer and cooler are common.
