  Vortices have been postulated at a range of size scales in the universe
including at the stellar size-scale. Whilst hydrodynamically simulating the
wind from an asymptotic giant branch (AGB) star moving through and sweeping up
its surrounding interstellar medium (ISM), we have found vortices on the size
scale of 10^-1 pc to 10^1 pc in the wake of the star. These vortices appear to
be the result of instabilities at the head of the bow shock formed upstream of
the AGB star. The instabilities peel off downstream and form vortices in the
tail of AGB material behind the bow shock, mixing with the surrounding ISM. We
suggest such structures are visible in the planetary nebula Sh 2-188.
