This book is in effect a second edition of a book first published by Wykeham
Publications in 1970. The Wykeham series was designed to bridge the gap
between school and university science and the mathematical level of the book was
designed to be suitable for sixth formers. In fact the main use of the book has been
as a university textbook and some of the mathematics which was then taught in
schools is now taught at university. In rewriting the book, I have not changed its
general level, but I have introduced two appendices containing more mathemat-
mathematical detail relating to topics discussed in the main text.
Many branches of physics such as gravitation, thermodyamics, atomic physics
and nuclear physics are combined in determining the structure of stars. As a result
the subject provides an ideal example of the application of fundamental physics.
Physical conditions in stars are more extreme than on Earth and a successful
understanding of their structure should show how valid it is to extrapolate
established physical laws to these conditions. Although it is profitable to study
stars as isolated objects, an understanding of star formation and stellar evolution
is central to the whole study of astronomy.