The stability and symmetry breaking bifurcation of a planar liquid drop is studied using the energy-Casimir method and singularity theory. It is shown that a rigidly rotating circular drop of radius
r with surface tension coefficient
and angular velocity
is stable if
2 < 3. A new brance of stable rididly rotating equilibria invariant under rotation through
and reflection across two axes bifurcates from the branch of circular solutions when
()2 = 3