Thermal Convective Instability in a Magnetised Isothermal Atmosphere

The problem of thermal instability in a uniformly rotating magnetized atmosphere was investigated. The corfiguration was assumed isothermal and characterized by a constant Alfven speed. The heat-loss mechanism was taken, for simplicity, to depend on temperature only. It was found than an inslability arises for all nonzero magnetic fields in an otherwise stable (static) configuration characterized by a heat-loss parameter which is an increasing function of temperature. The uniform rotation enhances the growth rates of the monotonically unstable modes in a fieldfree corfiguration. (auth)