Episodic Mass Loss and Pre-SN Circumstellar Envelopes

Understand

I discuss observational clues concerning episodic mass-loss properties of massive stars in the time before the final supernova explosion.

• In particular, I will focus on the mounting evidence that LBVs and related stars are candidates for supernova progenitors, even though current paradigms place them at the end of core-H burning.
• Namely, conditions in the immediate circumstellar environment within a few 10$^2$ AU of Type IIn supernovae require very high progenitor mass-loss rates.
• Those rates are so high that the only known stars that come close are LBVs during rare giant eruptions.