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This kinesthetic activity models the life of a

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small to medium size star, such as our sun. Each person

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involved in this activity represents a bit of the material that goes into making such a

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star. As the activity begins everyone is dancing or moving 

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around freely--just bits of matter that are hanging out in some particular spot in space.

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As these bits of matter come close to one another they start clumping

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together more and more, due to gravity. After a while

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this matter is clumped tightly enough to form a star. In our activity

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the participants at the edges form a ring facing inward, as the outer shell of the

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star, with their hands raised to represent the inwardly directed force of gravity.

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The participants in the center face outward, representing the core

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of the star, with their hands also raised to represent the energy generated by the

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fusion of hydrogen at the center of the star. These two forces

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remain in balance for most of the stars life. We call this a main

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sequence star. Eventually the star runs out of hydrogen to

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fuse in the core. And the balance of gravity and energy from fusion is broken.

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When this happens gravity wins and the participants in the core

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of the star drop their hands and move slightly closer together. The participants in the

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shell never lower their hands as gravity is always in effect.

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The slight decrease in the size of the core makes it hot and dense enough to start fusing

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helium. The participants in the core raise their hands once more as energy

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is again being generated at the center of the star. Participants in the 

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shell take a step outward to represent the surge in energy, making the star larger than

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it was during the main sequence phase. The star has become a red giant.

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Finally, the core of the star runs out of helium to 

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fuse. When this happens, the participants in the core once again drop their

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hands and move slightly closer together. This time the decreasing core

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size only raises the temperature enough to allow one last burst of energy,

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and push from the core. This causes the shell to drift away into space

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while the participants in the core move even closer together.

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At this stage the participants in the center represent a white dwarf while the 

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shell has drifted off to become a planetary nebula. Eventually the material

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that once formed the shell of the star will be available to be used in the formation

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of another star.

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Music

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