The magnetism of most celestial bodies, i.e., planets, stars, and galaxies, is of hydromagnetic origin. The turbulent hydromagnetic dynamo is the principal mechanism whereby the magnetic field is amplified and maintained, and the theory of this phenomenon has advanced significantly in recent years. This review discusses applications of the theory of the turbulent dynamo to real objects, taking the Sun, the Earth, and the Galaxy as examples. Most of the discussion is concentrated on the large-scale magnetic field averaged over turbulent fluctuations. The average field is amplified and maintained by the average helicity of turbulent motion and large-scale shear flows such as differential rotation. The dynamo theory explains striking phenomena such as geomagnetic field reversal, the solar cycle, and the ring and bisymmetric structure of spiral galaxies.

TY JOUR
TI The hydromagnetic dynamo as the source of planetary, solar, and galactic magnetism
AU Zeldovich, Ya. B.
AU Ruzmaikin, A. A.
PB Physics-Uspekhi
PY 1987
JO Physics-Uspekhi
JF Physics-Uspekhi
JA Phys. Usp.
VL 30
IS 6
SP 494-506
UR https://ufn.ru/en/articles/1987/6/c/
ER https://doi.org/10.1070/PU1987v030n06ABEH002852