SN 2009ip and SN 2010mc: Core-collapse Type IIn supernovae arising from blue supergiants

Understand

The recent supernova (SN) known as SN 2009ip had dramatic precursor eruptions followed by an even brighter explosion in 2012.

• Its pre-2012 observations make it the best documented SN progenitor in history, but have fueled debate about the nature of its 2012 explosion --- whether it was a true SN or some type of violent non-terminal event.
• Both could power shock interaction with circumstellar material (CSM), but only a core-collapse SN provides a self-consistent explanation.
• The persistent broad emission lines in the spectrum require a relatively large ejecta mass, and a corresponding kinetic energy of at least 10^51 erg, while the faint 2012a event is consistent with published models of core-collapse SNe from compact (~60 R_Sun) blue supergiants.