On the decay of the toroidal component of a large-scale stellar magnetic field

The problem of the decay of a large-scale stellar toroidal field is reformulated so as to take account of the strong dynamical coupling between poloidal and toroidal fields. Numerical results suggest that in an early-type star a surface toroidal field can survive over a stellar lifetime if the star has a hot corona, but if the coronal temperature is no higher than 10⁴K, an observable toroidal field will disappear unless it has an energy source.