  A neutron star contains regions with particles which exhibit magnetic
moments, which, in turn, generate respective magnetizations. By magnetoelastic
interactions between the magnetization and the matter there arises a
magnetostriction. The magnetostriction changes the mass density of the neutron
star and hence its inertia tensor, and as a result it changes the rotation
frequency of the star. We also sketch how the calculation of the
magnetostriction in the different inner regions of the neutron star has to
proceed, and which parameter inputs are needed.
