"Somehow, this zombie star has managed to survive one of the most powerful, destructive events known to science – multiple times. It should make us question, researchers wrote Wednesday in the journal Nature, how much we really know about supernovas."
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Assuming they were actually seeing the same star/supernova....and not another one or others nearby or behind it that they simply mistook for the same star/supernova.....then apparently the answer to the question "How much do they really know about supernovas?" might be....."not as much as they thought."