The observations of the peculiar Type IIn supernova SN2006gy in NGC1260 reveal that it is the most luminous supernova ever recorded. It requires a very massive progenitor star: the discoverers propose that the progenitor may have been a very massive evolved object like η Carinae that, contrary to expectations, failed to completely shed its massive hydrogen envelope before it died. This interpretation of SN2006gy implies that the most massive stars can explode earlier than expected, during the LBV phase, preventing them from ever becoming Wolf-Rayet stars.
See online : http://arxiv.org/abs/astro-ph/0612617