  The bremsstrahlung process Nu_Tau -> Nu_e E+ E- Gamma is the dominant
photon-producing decay of heavy Tau neutrinos with m_Nu_Tau > 2 m_e so that
this process is instrumental for supernova 1987A constraints on the properties
of these particles, notably on their mixing amplitude with Nu_e. We calculate
the rate of the bremsstrahlung process as well as the photon spectrum and the
angular distribution relative to the spin direction of the parent neutrino. We
carefully pay attention to the difference between Dirac and Majorana neutrinos.
