AST201H1 Lecture Notes - Lecture 6: Main Sequence, Low Mass
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AST201H1 Full Course Notes
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Bottom left = hotter and dimmer (white dwarfs) Stars not on the main sequences are not burning hydrogen in their cores. Stars not on the ms can have the same surface temperature as stars on the ms, but have a completely different luminosity. Fusion in the cores of main sequence stars. Only happens if there is tremendous temperature and pressure. Measuring the orbits lets us determine their masses. High mass stars have more pressure in their cores so nuclear fusion in core is much faster. High mass stars have "bigger tank" and brighter --> burn faster. More massive stars crush their cores more and burn hotter so they actually use up their fuel faster. Stars on the main sequence are burning hydrogen in their cores. Polaris and the sun have nearly the same temperature but polar has over 1000x higher luminosity. Many stars are in binary pairs, measuring orbits lets us determine mass.