Original: Almost every well-studied long gamma-ray burst has been associated with a rapidly star-forming galaxy and in many cases a core-collapse supernova as well, unambiguously linking long GRBs with the deaths of massive stars.
Simplified: Almost every well-studied long gamma-ray burst has been associated with a rapidly star-forming galaxy and in many cases a core-collapse supernova as well. This links long GRBs with the deaths of massive stars.