Pulsational pair instability as an explanation for the most luminous supernovae

Understand

The extremely luminous supernova SN 2006gy challenges the traditional view that the collapse of a stellar core is the only mechanism by which a massive star makes a supernova, because it seems too luminous by more than a factor of ten.

• Here we report that the brightest supernovae in the modern Universe arise from collisions between shells of matter ejected by massive stars that undergo an interior instability arising from the production of electron-positron pairs.
• This "pair instability" leads to explosive burning that is insufficient to unbind the star, but ejects many solar masses of the envelope.
• After the first explosion, the remaining core contracts and searches for a stable burning state.