Flame fronts in Type Ia supernovae and their pulsational stability

The structure of the deflagration burning front in Type Ia supernovae is considered. The parameters of the flame are obtained: its normal velocity and thickness. The results are in good agreement with the previous works of different authors. The problem of pulsation instability of the flame, subject to plane perturbations, is studied. First, with an artificial system with switched-off hydrodynamics the possibility of secondary reactions stabilizing the front is shown. Secondly, taking account of hydrodynamics and using a realistic equation of state (EOS) and thermal conduction, we can obtain pulsations when the Zeldovich number is artificially increased. The critical Zeldovich numbers are presented. These results show the stability of the flame in a Type Ia supernova against pulsations, because its effective Zeldovich number is small.