SIMBAD references

The effect of magnetic fields on the frequencies of toroidal oscillations of neutron stars is derived to lowest order. We suggest that the fine structure in the quasiperiodic oscillation power spectrum of magnetars following giant flares reported by Strohmayer & Watts is magnetic splitting of degenerate toroidal modes, and we estimate a corresponding crustal magnetic field on the order of 10¹⁵ Gauss or more. We suggest that residual m, -m symmetry following such splitting, together with nonaxisymmetric or rotational splitting of the residual symmetry, might allow beating of individual frequency components that is slow enough to be observed.