Revisiting the progenitor of the low-luminosity type II-plateau supernova, SN 2008bk

The availability of updated model atmospheres for red supergiants and improvements in single and binary stellar evolution models, together with previously unpublished data, prompted us to revisit the progenitor of the low-luminosity type II-plateau supernova (type IIP SN), SN 2008bk. Using mid-infrared (mid-IR) data in combination with dust models, we find that high-temperature (4250-4500 K), high extinction (E(B-V)> 0.7) solutions are incompatible with the data. We therefore favour a cool (similar to 3500-3700 K) progenitor with a luminosity of log(L/L-circle dot) similar to 4.53. Comparing with evolutionary tracks, we infer progenitor masses in the 8-10 M-circle dot range in agreement with some previous studies. This mass is consistent with the observed pattern of low-luminosity type IIP SNe coming from the explosion of red supergiant stars (RSGs) at the lower extremum for core collapse. We also present multi-epoch data for the progenitor, but do not find clear evidence of variability.

Automated summary

By combining mid-IR data with dust models, researchers found that the progenitor of SN 2008bk is likely a cool red supergiant with a luminosity of about 4.53. The inferred progenitor mass of 8-10 M⊙ is consistent with previous studies, suggesting that low-luminosity type IIP SNe may come from the explosion of red supergiant stars at the lower extremum for core collapse.