The thermomagnetic instability in degenerate cores of white dwarfs

The degenerate cores of sufficiently hot white dwarfs are shown to suffer the thermomagnetic instability which generates magnetic field and excites hydrodynamical motions. The necessary conditions for the instability to occur and the parameters of an unstable zone are determined. It is shown that, in hot white dwarfs, this zone can be very extended. The characteristic time scale of the instability is evaluated and some effects due to this instability are discussed. (orig.)