RESUMEN

This paper studies the effect of magnetic field on the convective instability of a radiating fluid in a porous medium confined between two rotating cylinders. The temperatures of the walls of the cylinders are large but the temperature difference is small so that the radiative flux equation could be linearized. Only for very small radiation parameter, of order 0(0.01), does instability first set in via adverse temperature gradient. Otherwise rotational instability is more fatal.