  We calculate the emission spectrum for vacuum Cerenkov radiation in
Lorentz-violating extensions of electrodynamics. We develop an approach that
works equally well if the presence or the absence of birefringence. In addition
to confirming earlier work, we present the first calculation relevant to
Cerenkov radiation in the presence of a birefringent photon k_F term,
calculating the lower-energy part of the spectrum for that case.
