Typical Magnetic Field Strengths
Object Strength (Gauss)
Earth (surface) 0.6
Simple iron bar magnet 100
Strongest sustained
laboratory fields
4 x 105
Strongest man-made fields (millisecond duration) 107
Maximum field for ordinary stars 106
Typical radio pulsars 1012
Magnetars 1014 - 1015

Magnetic Fields

Neutron stars have very strong magnetic fields that are responsible for many of their striking properties. The adjacent table gives some typical magnetic field strengths for objects of interest in astronomy (a Gauss is a common unit of magnetic field strength). The entries marked "radio pulsars" and "magnetars" are associated with particular kinds of neutron stars. Clearly, neutron stars lead to the largest magnetic fields observed in nature.

The following diagram illustrates the magnetic field of a rapidly spinning neutron star. We shall have more to say about this field when we discuss pulsars in the next module.