AST-1A Lecture Notes - Lecture 15: Sn 1572, Sn 1054, Sn 1006
Document Summary
3*10^8 m/s * 31 * 10^7+ 9 * 10 ^15 m or about 10^16. After about 2 hours, burst of x-ray, uv- yes a threat. After year, nuclear radiation- is a threat. After 10 years, shock wave reached ring, high pressure, energetic particles. Supernovae a threat at 25-50 light years, can destroy ozone layer. Red supergiant-a massive star spends about 10% of its life in this late phase. Should explode anytime within a million years. Need within about 30 light years to be a threat. Extragalactic supernovae- been used to prove that the universe is accelerating. Thermonuclear type 1a - explosion of a white dwarf (sn 1006, sn 1572, sn 1604)- doesn"t have hydrogen. Core collapse type ii, 1b/c massive star (sn 1054, sn 1987a, cas a) In low mass stars the core will never get hot enough to burn carbon. Gravity continues to cause the core to collapse until the density is nearly a million times that of water.
