  The present article investigates the impact of muons on core-collapse
supernovae, with particular focus on the early muon neutrino emission. While
the presence of muons is well understood in the context of neutron stars, until
the recent study by Bollig et al. [Phys. Rev. Lett. 119, 242702 (2017)] the
role of muons in core-collapse supernovae had been neglected--electrons and
neutrinos were the only leptons considered. In their study, Bollig et al.
disentangled the muon and tau neutrinos and antineutrinos and included a
variety of muonic weak reactions, all of which the present paper follows
closely. Only then does it becomes possible to quantify the appearance of muons
shortly before stellar core bounce and how the post-bounce prompt neutrino
emission is modified
