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Gigantic balls of hot, whirling gases that race through the atmosphere are know as stars. On a clear, dark night away from bright city lights and tall buildings a person could see over 2,000 stars with the naked eye. The best known star in our solar system is 93 million miles from Earth and called the Sun. Like the Sun, most stars are much larger than Jupiter, which is the biggest planet in our solar system. In fact there are stars so huge that our sun could fit inside them over a million times.
Stars appear small to us here on earth because they are trillions of miles away. Even the closest star to our planet, Alpha Centauri, is over 25 million miles from earth. It is believed that stars appear in groups called constellations. In ancient times people named these groups of stars according to what or who they believed these groups appeared to be. Thus a crown became Corona Borealis. A lion became Leo, a wolf became Lupus or a bear became Ursa Major. Even the Big Dipper was so named because it appeared as a huge dipper in the night sky.
Although many people believe that stars twinkle, they are a steady shining light. Light rays coming from the stars are bent as they pass through the layers of atmosphere causing us to perceive them as twinkling. The surface of most stars can range in temperature from 5500 degrees fahrenheit up to 19,000 degrees fahrenheit. All stars are hot but the color of a star depends on its temperature. Red stars are the coolest while yellow stars like the sun are medium hot. The hottest stars are those that appear to be blue. Most stars are around for millions of years but when the life of a star is over smaller stars burn up, while larger stars break up into supernovas.