Astronomy 1021 Chapter 17: Chapter 17 Summary Cosmic Perspective
4 Jan 2012
School
Department
Course
Professor
Document Summary
Low mass stars like our sun live long lives and die by producing planetary nebulae that leave behind white dwarfs. High mass stars live fast and die young exploding dramatically as supernovae and leaving behind neutron stars or black holes. Close binary stars can exchange mass thus altering the usual course of stellar evolution. Elements needed for life of high mass stars: Red giant: a giant star that is red in colour. Hydrogen shell burning: hydrogen fusion that occurs in a shell surrounding a stellar core. Helium flash: the event that marks the sudden onset of helium fusion in the previously inert helium core of a low mass star. Helium fusion: the fusion of three helium nuclei into one carbon nucleus. Thermal pulses: the predicted upward spikes in the rate of helium fusion occurring every few thousand years that occur near the end of a low mass star s life.
