There is observational evidence of a dearth in core-collapse supernova ( ccSN ) explosions from stars with zero age main sequence ( ZAMS ) mass M _ { 0 } \approx 17 - 30 \mathrm { M } _ { \odot } , referred to as the ‘ red supergiant problem ’ .
However , simulations now predict that above 20 M _ { \odot } we should indeed only expect stars within certain pockets of M _ { 0 } to produce a visible SN explosion .
Validating these predictions requires large numbers of ccSNe of different types with measured M _ { 0 } , which is challenging .
In this paper we explore the reliability of using host galaxy emission lines and the H \alpha equivalent width to constrain the age , and thus the M _ { 0 } of ccSNe progenitors .
We use Binary Population and Spectral Synthesis models to infer a stellar population age from MUSE observations of the ionised gas properties and H \alpha EW at the location of eleven ccSNe with reliable M _ { 0 } measurements .
Comparing our results to published M _ { 0 } values , we find that models that do not consider binary systems yield stellar ages that are systematically too young ( thus M _ { 0 } too large ) , whereas accounting for binary system interactions typically overpredict the stellar age ( thus underpredict M _ { 0 } ) .
Taking into account the effects of photon leakage bring our M _ { 0 } estimates in much closer agreement with expectations .
These results highlight the need for careful modelling of diffuse environments , such as are present in the vicinity of type II SNe , before ionised emission line spectra can be used as reliable tracers of progenitor stellar age .