With new observations delineating the large-scale magnetic fields in galaxies and renewed interest in the influence of magnetic fields on star formation and on the collimation of jets, this book provides a timely review of cosmic magnetohydrodynamics. The book has a broad sweep, from the theory of the Earth's dynamo through the magnetically-dominated Solar corona to the magnetic fields of stars, galaxies, quasars and the intergalactic plasma. Particular emphasis is given to the magnetic fields of degenerate stars. Both white dwarfs and the evolution of neutron stars' magnetic fields are discussed in detail. The book is dedicated to Professor Leon Mestel who has seen the subject grow from its early days to its current position. Stellar winds, cosmic rays, galactic dynamos, active galactic nuclei and black holes provide a wide range for both scientific imagination and precise deduction. Many of the creators of the subjects have contributed to this volume, which should be useful reading for astronomy graduate students with magnetic interests as well as plasma physicists.Magnetic fields may play the dominant role in collimating the jets from radio galaxies, quasars and young stellar objects. Black holes, neutron stars and white dwarfs have magnetospheres whose properties are not yet fully understood. The Solar corona is dominated by magnetism and is electrically heated. The theory and observations of these magnetic fields are reviewed here by a number of experts on astronomy and dynamo theory.
