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Chapter 25

Nuclear fusion and stars

LEARNING OBJECTIVES

In this chapter you will learn how to:

●recognize the conditions for nuclear fusion to occur

●calculate the energy released in fusion reactions

●explain why energy is released in fusion

●understand why the conditions for fusion exist in stellar cores

●recognize the role of stellar mass in the evolution of the star

●understand the proton–proton chain

●use stellar radii and the Hertzsprung–Russell (HR) diagram

●describe the evolution of a star off the main sequence

●understand the Chandrasekhar and Oppenheimer–Volkoff limits, white dwarfs, neutron stars and black holes

GUIDING questions

●What determines the evolution of a star?

●What is the origin of the elements?