  We investigate the low-luminosity supernova SN 2016bkv and its peculiar
early-time interaction. For that, we compute radiative transfer models using
the CMFGEN code. Because SN 2016bkv shows signs of interaction with material
expelled by its progenitor, it offers a great opportunity to constrain the
uncertain evolutionary channels leading to low-luminosity supernovae. Our
models indicate that the progenitor had a mass-loss rate of (6.0 +- 2.0) x 1e-4
Msun/yr (assuming a velocity of 150 km/s). The surface abundances of the
progenitor are consistent with solar contents of He and CNO. If SN 2016bkv's
progenitor evolved as a single star, it was an odd red supergiant that did not
undergo the expected dredge up for some reason. We propose that the progenitor
more likely evolved through binary interaction. One possibility is that the
primary star accreted unprocessed material from a companion and avoided further
rotational and convective mixing until the SN explosion. Another possibility is
a merger with a lower mass star, with the primary remaining with low N
abundance until core collapse. Given the available merger models, we can only
put a loose constraint on the pre-explosion mass around 10-20 Msun, with lower
values being favored based on previous observational constraints from the
nebular phase.
