The main structure of the first edition has been retained, but we have taken the opportunity in this second edition to update the text and clarify an occasional obscurity. The text has in places been expanded, and also additional topics have been added. The growing interest of physics students in astrophysics has encouraged us to extend our discussions of the nuclear and neutrino physics of supernovae, and of solar neutrinos. There is a new chapter devoted to neutrino masses and neutrino oscillations. In other directions, a description of muon-catalysed fusion has been included, and a chapter on radiation physics introduces an important applied field.

We should like to thank Dr John Andrews and Professor Denis Henshaw for their useful comments on parts of the text, Mrs Victoria Parry for her secretarial assistance, and Cambridge University Press for their continuing support.