LIFECYCLE OF A STAR

TYPES OF STARS Dwarfs - Smaller stars are called dwarf stars. Red and yellow stars are generally called dwarfs. A white dwarf is the remnants of the collapse of a red giant star. Giants - Giant stars may be main sequence stars like a blue giant, or stars that are expanding like red giants. Some supergiant stars are as big as the entire Solar System! Neutrons - A neutron star is created from the collapse of a giant star. It's very tiny, but very dense

BIRTH OF A STAR Stars start out in giant clouds of dust called nebulae. Gravity forces the dust to bunch together. As more and more dust bunches up, gravity gets stronger and it starts to get hot and becomes a protostar. Once the center gets hot enough, nuclear fusion will begin and a young star is born.

MAIN SEQUENCE STAR Once a star is formed, it will continue to burn energy and glow for billions of years. This is called the "main sequence". A star stays this way for the majority of its life. During this time a balance is met between gravity wanting to shrink the star and heat wanting to make it grow bigger. The star will remain in this balance until it runs out of hydrogen.

RED GIANT When the star runs out of hydrogen the outside expands and it becomes a red giant

COLLAPSE OF THE STAR Eventually the core of the star will start to make iron. This causes the star to collapse. The average star will become a white dwarf star. Larger stars will make a huge nuclear explosion called a supernova. After the supernova it may become a black hole or a neutron star.

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