MICROSCOPIC INSTABILITIES OF NUCLEAR FLAMES IN TYPE IA SUPERNOVAE

Hydrodynamic instabilities on microscopic scales in Type Ia supernovae are studied by means of two-dimensional numerical simulations. We cal l attention to the fact that on linear scales not much larger than the width of the burning front, the Landau-Darrieus instability leads to a growth of perturbations, thereby wrinkling the flame and increasing its surface area. It is expected that this instability will accelerate the front on small scales beyond its laminary velocity, although the effect is not apparent in the results of the simulations. A brief disc ussion of the instability in the nonlinear regime, which was not reach ed in our numerical experiments, is also given.