  The Schwarzschild interior solution, or `Schwarzschild star', which describes
a spherically symmetric homogeneous mass with constant energy density, shows a
divergence in pressure when the radius of the star reaches the
Schwarzschild-Buchdahl bound. Recently Mazur and Mottola showed that this
divergence is integrable through the Komar formula, inducing non-isotropic
transverse stresses on a surface of some radius $R_{0}$. When this radius
approaches the Schwarzschild radius $R_{s}=2M$, the interior solution becomes
one of negative pressure evoking a de Sitter spacetime. This gravitational
condensate star, or gravastar, is an alternative solution to the idea of a
black hole as the ultimate state of gravitational collapse. Using Hartle's
model to calculate equilibrium configurations of slowly rotating masses, we
report results of surface and integral properties for a Schwarzschild star in
the very little studied region $R_{s}<R<(9/8)R_{s}$. We found that in the
gravastar limit, the angular velocity of the fluid relative to the local
inertial frame tends to zero, indicating rigid rotation. Remarkably, the
normalized moment of inertia $I/MR^2$ and the mass quadrupole moment $Q$
approach to the corresponding values for the Kerr metric to second order in
$\Omega$. These results provide a solution to the problem of the source of a
slowly rotating Kerr black hole.
