1. Chapters 14 and 15 Stellar Evolution and Stellar Remnants

2. Star Birth: Nebula

3. Young star: Protostar

4. As the temperature in the interior rises, nuclear reactions produce outward force and balances the inward force of gravity  hydrostatic equilibrium = star becomes stable and contraction stops  main-sequence star Adult: Main Sequence

5. Energy Sources in Stars 4 hydrogen nuclei fuse to become 1 helium nucleus Since the mass of 4 hydrogen nuclei is greater than the mass of 1 helium nucleus, the leftover mass (0.7%) is converted to energy by Einstein’s equation: E=mc 2

6. The more massive a star, the faster it consumes its fuel, the shorter its lifetime The end states of stars depends upon its mass!

7. A B C

8. Evolution of Low Mass Stars including our Sun M < 10 Solar Masses

9. Old Age: Red Giant

11. Elderly, core: White Dwarf The core of the white dwarf star is now all carbon and oxygen

12. Ring NebulaEskimo Nebula Elderly, envelope: Planetary nebula

13. Yeah, but what about the really Massive stars?

14. Old Age: Red Supergiant

16. Figure 13.19 Elderly, dying star: Supernova

17. Super Nova Remnants

18. Our Sun will never explode. Only massive stars explode as supernova!

19. Elderly, core: Neutron Star Core High mass stars becomes so dense that protons and electrons combine to become neutrons and star becomes neutron star

20. Life Cycle of a Low Mass Star

21. Life Cycle of a High Mass Star