  The next galactic core-collapse supernova will deliver a wealth of neutrinos
which for the first time we are well-situated to measure. These explosions
produce neutrinos with energies between 10 and 100 MeV over a period of tens of
seconds. Galactic supernovae are relatively rare events, occurring with a
frequency of just a few per century. It is therefore essential that all
neutrino detectors capable of detecting these neutrinos are ready to trigger on
this signal when it occurs. This poster describes a data-driven trigger which
is designed to detect the neutrino signal from a galactic core-collapse
supernova with the NOvA detectors. The trigger analyzes 5ms blocks of detector
activity and applies background rejection algorithms to detect the signal time
structure over the background. This background reduction is an essential part
of the process, as the NOvA detectors are designed to detect neutrinos from
Fermilab's NuMI beam which have an average energy of 2GeV--well above the
average energy of supernova neutrinos.
