  We show that in the framework of noncommutative classical electrodynamics
Cherenkov radiation is permitted in vacuum and we explicitly compute its
spectrum at first order in the noncommutative parameter. We discuss the
phenomenological impact of the merge of this new analysis with the old results
of the substantial modification to the spectrum of the synchrotron radiation
obtained in P.Castorina, A.Iorio and D.Zappala, Phys. Rev. D 69 (2004)065008.
We propose to consider the pulsars' radiation spectrum - due to its very strong
magnetic field - to investigate these Lorentz violating effects in
astrophysical phenomena.
