Origin of the magnetic fields of the earth and celestial bodies

Various mechanisms for the generation of cosmic magnetic fields are analyzed from the standpoint of the possible application of these mechanisms to the earth and to specific celestial objects. The analysis focuses on nondynamo mechanisms. The generation of a field by a “battery” process at chemically peculiar Cp stars is analyzed. The important role played by meridional streams in the generation of fields at O and B stars is pointed out. The effect of chemical and temperature variations at the boundary between the earth's core and mantle on the generation of the terrestrial field is discussed. A thermomagnetic instability may play an important role in generating the field of white dwarfs and, possibly, neutron stars. An induction mechanism for field generation in close binary stars is examined. The distinctive features of the magnetic fields of the sun and of convective stars are discussed.