Luminous blue variables and the fates of very massive stars

Luminous blue variables (LBVs) had long been considered massive stars in transition to the Wolf-Rayet (WR) phase, so their identification as progenitors of some peculiar supernovae (SNe) was surprising. More recently, environment statistics of LBVs show that most of them cannot be in transition to the WR phase after all, because LBVs are more isolated than allowed in this scenario. Additionally, the high-mass H shells around luminous SNe IIn require that some very massive stars above 40 M_⊙ die without shedding their H envelopes, and the precursor outbursts are a challenge for understanding the final burning sequences leading to core collapse. Recent evidence suggests a clear continuum in pre-SN mass loss from super-luminous SNe IIn, to regular SNe IIn, to SNe II-L and II-P, whereas most stripped-envelope SNe seem to arise from a separate channel of lower-mass binary stars rather than massive WR stars.This article is part of the themed issue 'Bridging the gap: from massive stars to supernovae'.