Astronomy 1021 Chapter Notes - Chapter 13: Protostar, Melting Point, Solar Mass
16 Aug 2016
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Document Summary
The space between the stars seems largely empty. But there"s a fair amount of material between the stars o o o o. They are in form of low-density gas (h and he) They do contain about 1% of heavier elements called dust. Their overall composition is similar to the sun"s. Emission nebulae- hot gas emits light (red) Nebulae are about 50-300 light years across: grand scale. They form through gravitational contraction: but they will only contract if they are really massive so its gravity is strong, giant molecular cloud (gmc) As it contracts, thermal pressure, turbulence, and magnetic fields resists contraction. To get rid of thermal pressure/kinetic energy through molecular line emission: o. Convert kinetic energy into radiation in emission of infrared. A nebula can break up into smaller part. Now smaller mass is required is needed to win against pressure: dense clumps can contract on their own o.
