ON HYDRODYNAMIC STABILITY OF WEAKLY MAGNETIZED STELLAR RADIATIVE ZONES

We consider the stability of weakly magnetized differentially rotating stars to adiabatic axisymmetric disturbances. The general case of the angular velocity being dependent on both the spherical radius and the polar angle is analysed. In magnetized radiative zones, there are two low-frequency modes, the buoyant and torsion Alfven ones, which can b e destabilized by a differential rotation. For instability, the buoyan t mode requires a decrease of the specific angular momentum in the dir ection from the poles to the equator, whereas the Alfven mode can be u nstable if the angular velocity decreases from the poles to the equato r. A relatively strong magnetic field may stabilize both of these mode s.