  The equation of state of SU(3) Yang-Mills theory can be modelled by an
effective $Z_3-$symmetric potential $V(\vert\phi\vert,\phi^3+\phi^{3*}, T)$
depending on the temperature $T$ and on a scalar field $\phi$ -- the averaged
Polyakov loop. Allowing $\phi$ to be dynamical opens the way to the study of
spatially localized classical configurations of the Polyakov loop. We first
show that spherically symmetric static Q-balls exist in the range
$(1-1.21)\times T_c$, $T_c$ being the deconfinement temperature. Then we argue
that Q-holes solutions, if any are unphysical within our framework. Finally we
couple the Polyakov-loop Lagrangian to Einstein gravity and show that
spherically symmetric static boson stars exist in the same range of
temperature. The Q-ball and boson star solutions we find can be interpreted as
"bubbles" of deconfined gluonic matter; their mean radius is always smaller
than 10 fm.
