Observational constraints on the progenitor of core-collapse supernovae

It is well-known that some massive stars evolve to an end state which results in the collapse of the stellar core, as the hydrostatic pressure can no longer support gravity, leading to powerful explosions called supernovae (SNe). Even with over 6000 known SNe, we have only direct information about the progenitor star for a handful of explosions. Here, I summarise the observational constraints of the massive progenitor stars of several core-collapse supernovae