AST201H1 Lecture Notes - Lecture 8: Degenerate Matter, Electron Degeneracy Pressure, White Dwarf

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Michael Reid

Document Summary

Nuclear fusion rate would decreases lowers core pressure causes core to contract and heat up. Explain why our sun will expand after it fuses all of its core hydrogen and moves off of the main sequence. Use a diagram to show how the sun will move in the hr diagram when this happens. When the star"s core hydrogen is depleted, nuclear fusion will cease. No core fusion= no pressure to prevent the gravity from collapsing the core. So core shrinks as gravity compresses the core until it is hot enough for hydrogen shell burning. High rate of fusion in the hydrogen shell forces the star"s outer layers to expand outward (while core continues to shrink) The sun cannot fuse elements heavier than helium in its core after the main sequence: why is this and why do massive stars not have this problem. After silicon becomes iron in the core, no fusion can occur in the core.