When you look at the stars at night they all look to be the same. In reality they are all very different. Each has it's own unique color, temperature, and size.
A giant star is a star with it's atoms spread out. An average star is a star that is not as big as a giant star, but not as small as a dwarf star. A dwarf star is a star with it's atoms packed together.
The first dwarf to be discovered was the Pup. The Pup circles around a giant star called Sirius. Although nobody can see the pup we know it is there. It circles around Sirius about every 50 years pulling Sirius to the side.
Here is an example of a giant star named Betelgeuse compared to our Sun and the Earth.
Betelgeuse is about 500 million miles in diameter. It is so big that if it were the center of our solar system, the planets all the way out to mars would be inside the star. Betelgeuse is a red super giant.
The temperture of stars depend on the color. Here is a meter showing how hot different color stars are.
Stars go through a lifetime, just like us. Theyr'e born, they live, they die. After the star dies, a nebula is formed. In these nebulas astronomers have found globules. Since stars are believed to come from these dense balls of dust and gas, these globules are called ''stellar nurseries.'' These globules become a star. How? Since these globules have more gravitational attraction than the dust and gas surrounding them they can pull matter into them, and grow. As they grow, bigger their gravitational atraction increases, and a star is born.
For more information visit the following sites:
http://www.geocities.com/CapeCanaveral/Launchpad/1364/Stars.html
http://www.astro.wisc.edu/~dolan/constellations/constellations.html
