The Corotation Radius ``Ecology'' of Magnetic Rotators The Stopping Radius in

Effect of the Magnetic Field

 

Apparently, the magnetic field of a star becomes significant only when the stopping radius exceeds the radius of the star, . We take the Alfven radius for , since it is the smallest of the two quantities and . Hence, we can estimate the lowest value of magnetic field of a star which will influence the flow of matter

The case , is considered most frequently, and for this case we get the following numerical estimations

or, equivalently,

Most presently observed NS have magnetic fields  G and dipole moments  G cm , so the magnetic field must necessarily be taken into account when considering interaction of matter with these stars.