Gravity Holds a Star Together

Gravity Holds a Star Together - Gravity Holds a Star...

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Gravity Holds a Star Together Stars are held together by gravity. Gravity tries to compress everything to the center. What holds an ordinary star up and prevents total collapse is thermal and radiation pressure. The thermal and radiation pressure tries to expand the star layers outward to infinity.
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Hydrostatic equilibrium: gravity compression is balanced by pressure outward. Greater gravity compresses the gas, making it denser and hotter, so the outward pressure increases. In any given layer of a star, there is a balance between the thermal pressure (outward) and the weight of the material above pressing downward (inward). This balance is called hydrostatic equilibrium . A star is like a balloon. In a balloon the gas inside the balloon pushes outward and the elastic material supplies just enough inward compression to balance the gas pressure. In a star the star's internal gravity supplies the inward compression. Gravity compresses the star into the most compact shape possible: a sphere. Stars are round because gravity attracts everything in an
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Gravity Holds a Star Together - Gravity Holds a Star...

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