Matt Nicholl (Queen's University Belfast): What powers the brightest supernovae?

In the last decade, unbiased transient surveys have discovered a number of supernovae that are 10-100 times brighter than previously known supernova types; these have been classified as "super-luminous" supernovae. The mechanism which powers their extreme luminosities is still unclear. Popular theories include spin-down of a millisecond magnetar, very high radioactive nickel masses from 'pair-instability? explosions, and collisions between massive shells of dense material. I will review the current state of research into these rare and mysterious transients, report on observations of super-luminous supernovae from Pan-STARRS1 and PESSTO, and show how light curve modelling is slowly revealing the underlying physics.