  The vacuum solutions arising from a spontaneous breaking of Lorentz symmetry
due to the acquisition of a vacuum expectation value by a vector field are
derived. These include the purely radial Lorentz symmetry breaking (LSB),
radial/temporal LSB and axial/temporal LSB scenarios. It is found that the
purely radial LSB case gives rise to new black hole solutions. Whenever
possible, Parametrized Post-Newtonian (PPN) parameters are computed and
compared to observational bounds, in order to constrain the Lorentz symmetry
breaking scale.
