  We present a stationary spherically symmetric solution of the Einstein
equations, with a source generated by a scalar field of $q$-theory. In this
theory Riemannian gravity, as described by the Einstein - Hilbert action, is
coupled to a three - form field that describes the dynamical vacuum. Formally
it behaves like a matter field with its own stress - energy tensor, equivalent
to a scalar field minimally coupled to gravity. The asymptotically flat
solutions obtained to the field equations represent black holes. For a
sufficiently large horizon radius the energy density is localized within a thin
spherical shell situated just outside of the horizon, analogous to a gravastar.
The resulting solutions to the field equations, which admit this class of
configurations, satisfy existence conditions that stem from the Black Hole no -
hair theorem, thanks to the presence of a region in space in which the energy
density is negative.
