DETAILED MAPPING OF EXTREME MASS LOSS WITH COORDINATED NUSTAR-XMM OBSERVATIONS

Contrary to expectations from current stellar evolutionary models, recentobservations uncovered the ejection of shells of material by massivestars in the years before the supernova (SN) explosion. The physicalmechanism behind the impulsive mass ejection synchronized with the stellarcorecollapse is unclear. Here we propose a coordinated NuSTARXMM effortto map the evolution of the broadband Xray spectrum of 1 nearby (d<50Mpc) strongly interacting SN and enable progress. Our program has theimmediate goal to characterize the medium around strongly interacting SN,which originate from stellar progenitors with the most extreme mass lossbefore explosion. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]