Stellar evolution has become one of the most active topics of research in astrophysics in recent years. At first, attention was centered around various nuclear processes inside stars, but it has now expanded to cover processes that before could be considered only in a speculative way, including neutron stars and gravitational waves. This book encompasses the full range of the subject. Its articles are presented for the most part in the order of the life of a star—from main sequence stars through white dwarfs, novae, and supernovae, to neutron stars—beginning with basic principles and developing into problems of current interest. The 22 articles are based on lectures given by some of the world"s most outstanding astrophysicists at the Third Summer Institute for Astronomy and Astrophysics held at the State University of New York at Stony Brook. The first three articles trace the life of stars from the onset of nuclear burning, through their stay within the main sequence, partial hydrogen exhaustion, and the red giant stage, to the white dwarf stage or carbon ignition. The next article takes up the special case of massive main-sequence stars with their attendant instabilities caused by high radiation pressure. Pulsations and variable stars and their applications to realistic star models, including nonlinear effects, are studied next. The following article describes recent refinements in the understanding of white dwarfs. Some close binaries are believed to be progenitors of novae. Three articles take up successively the structure and life history of close binaries, novae, and supernovae. The last known stage of stellar life follows complete gravitational collapse. Under immense densities electrons "combine" with protons to produce neutron stars, of which pulsars are examples. Two articles survey their properties and present some theoretical interpretations. The remaining articles cover a number of specific areas of interest, including photometry of field horizontal-branch stars, helium abundances, opacity, transport mechanisms, thermonuclear reactions and nucleosynthesis, the instabilities associated with nuclearburning shells, magnetic fields, and stellar collision. In addition, an account of relativistic stars and gravitational waves has been written to accommodate non-specialists in this field. The contributors are Icko Iben, Jr., P. Demarque, B. Paczynski, R. Stothers, N. Baker, R. F. Christy, J. P. Ostriker, W. K. Rose, Stirling A. Colgate, Chester McKee, A. G. W. Cameron, Hong-Yee Chiu, A. G. Davis Philip, S. E. Strom, T. Richard Carson, E. A. Spiegel, J. W. Truran, K. S. Thorne, L. Mestel, and V. Canuto.