  An analysis of the propagation of non stationary waves in the adiabatic
region of stellar interior is presented. An equation of motion with an
effective potential is derived, similar to the Zerilli equation known in the
propagation of gravitational waves. The Huyghens principle is violated in this
case and the energy diffusion outward null cones is expected. Numerical
calculations demonstrate that the diffusion is weak for the case of standard
Solar model; thus no significant effect corresponding to quasinormal modes can
be expected. The likely reason for the absence of stronger features is the
restriction of our analysis to adiabatic regions only, where the breakdown of
the Huyghens principle is insignificant.
