Cooling of magnetic flux tubes as a mechanism for suppression of magnetic buoyant escape of the flux tubes from the sun and stars

A new mechanism to suppress the magnetic buoyancy of flux tubes in the solar and stellar convection zones is proposed as a solution of the enigma that the very convective stratification, that drives plasma fluid motions to generate magnetic fields, is unfavorable to keep the generated fields because of the magnetic buoyancy. The mechanism is cooling of flux tubes by inhibition of convective heat transport by magnetic fields inside the tubes that could also be responsible for the cooling of sunspots, starspots, and pores. The cooling inside a tube, in which energy is supposed to be transported mostly by radiation, comes from a steeper fictitious radiative temperature gradient than that of averages urroundings in a convectively unstable layer. Because of extremely small values of the temperature difference to suppress the magnetic buoyancy and because of the extremely small values of the associated radial distance over which the temperature gradients in the flux tubes and in the surroundings must be integrated to attain the temperature difference, it is suggested that the cooling mechanism as a stabilizing mechanism of the magnetic buoyancy is plausible.