The superspinar proposed by Gimon and Horava is a rapidly rotating compact
entity whose exterior is described by the over-spinning Kerr geometry. The
compact entity itself is expected to be governed by superstringy effects, and
in astrophysical scenarios it can give rise to interesting observable
phenomena. Earlier it was suggested that the superspinar may not be stable but
we point out here that this does not necessarily follow from earlier studies.
We show, by analytically treating the Teukolsky equations by Detwiler's method,
that in fact there are infinitely many boundary conditions that make the
superspinar stable, and that the modes will decay in time. It follows that we
need to know more on the physical nature of the superspinar in order to decide
on its stability in physical reality.Comment: 5 page
