ASTRON 1101 Lecture Notes - Lecture 22: Electron Degeneracy Pressure, White Dwarf, Blue Supergiant Star
19 Oct 2016
School
Department
Course
Professor
Document Summary
High-mass stars have a mass of over 4 times the mass of the sun. High-mass stars are very luminous and this spend a short time on the main sequence. Main example: a star with m = 10 msun, l = 10,000 lsun, and tnuc = 10 million years. High-mass stars live fast and die young (often in a spectacular manner) The main sequence phase of a high-mass star is like that of a low-mass star, only speeded up. All energy generation is by fusion of hydrogen (h) to helium (he) in the cno cycle. During 10 million years, the star builds up an inert he core. The core hydrogen runs out, the inert helium core starts to shrink. Hydrogen fusion is ignited in a thin shell above the contracting core. During 1 million years, the star moves horizontally across the h-r diagram (constant l, decreasing t, increasing r)
