Most stars appear to show some degree of magnetic activity. Varying magnetic fields show up in the familiar sun-spot cycle and in similar activity in other cool stars. Many hot stars carry steady magnetic fields stronger than the average solar field and are well described as oblique rotators. A similar model is applicable to the rapidly rotating, enormously dense neutron stars with their far stronger fields, observed as radio and X-ray pulsars. Galactic magnetic fields may play a crucial role in star formation, and in the spectacular behaviour in galactic nuclei. Cosmical magnetism in general is a rapidly developing field, and this book has grown out of the lifelong work of an outstanding researcher in the area. An authoritative account with broad astronomical scope, its thorough, careful and well-argued approach makes it a fine addition to the professional literature. Most of the important topics are treated in mathematical depth with references to other relevant literature. Some of the studies, especially those on accretion discs, dynamos, and winds, are applicable to galaxies and galactic nuclei. This book is sure to become an invaluable professional reference and guide to current thinking in the field. It will be of particular interest to graduate students, for whom it shows how the area has developed and indicates the many challenging research problems, some of which may soon yield their secrets to the emerging supercomputers.

Ongoing studies in mathematical depth, and inferences from helioseismological' observations of the internal solar rotation have shown up the limitations in our knowledge of the solar interior and of our understanding of the solar dynamo, manifested in particular by the sunspot cycle, the Maunder minimum, and solar flares. This second edition retains the identical overall structure as the first edition, but is designed so as to be self-contained with the early chapters presenting the basic physics and mathematics underlying cosmical magnetohydrodynamics, followed by studies of the specific applications appropriate for a book devoted to a central area in astrophysics.
New to this edition:
Chapter 6 gives an account of the present state of dynamo theory in general, and Chapter 8 the applications to the Sun and to other Late-Type' stars with differing rotation rates -- the Solar-Stellar Connection'. The minority of the more massive Early-Type' stars that are observably magnetic are well described by theoblique rotator' model, with a quasi-steady, fossil' magnetic structure frozen' into the highly conducting, non-turbulent envelope. Chapter 9 deals with the considerable progress on the associated theoretical problems.
Chapter 7 contains new material, relevant to both Late- and Early-Type Main Sequence stars, to the evolved Red Giants, and also to contracting pre-Main Sequence stars (Chapter 10}, which show the highest degree of magnetic activity (the magneto-rotational instability, and the magneto-centrifugal winds emitted by the surrounding accretion disk'). In the earlier phases of star formation in molecular clouds (Chapters 11-12), magneto-turbulence' is emerging as the appropriate scenario for the prediction of the mass spectrum of proto-stars, and the associated formation of planetary satellites. Chapter 14 describes developments in the study of the magnetosphere of a pulsar' -- a magnetized neutron star -- consisting of spontaneously generated electron-positron pairs.

Stellar magnetism is the study of the magnetic field of the Sun and other stars and is a rapidly developing field of astrophysics. This book, an authoritative account with broad astronomical scope, has grown out of the lifelong work of an outstanding researcher in the subject.