Modeling a core collapse supernova
(PHYSorg.com Space & Earth)

Stars greater than eight solar-masses end their lives spectacularly-as supernovae. These single-star supernovae are called core collapse supernovae because when their dense cores (at this stage composed primarily of iron) are no longer able to withstand the inward pressure of gravity they collapse inward before exploding. Core collapse supernovae with strong hydrogen emission lines are thought to result from the explosions of red supergiant stars, massive stars that have evolved beyond their principle hydrogen burning stage and grown in radius. Until recently, astronomers thought these stars were relatively quiescent until their final demise, but evidence has been accumulating that they actually experience strong mass loss before exploding. In some models, emission resulting when ejecta from the supernovae encounter these envelopes produces the observed variations in core collapse supernova.