Gravitational Waves: Did Merging Black Holes Form from Single Star?

Could a single, dying star give birth to not one, but two black holes? Scientists have long held different ideas about how black holes of this size get close enough to collide, but another proposal has just entered the ring: that the black holes were created, shortly before their collision, from one, massive star as it was collapsing in on itself. This new hypothesis posits that the merger of these two black holes would produce light — including, possibly, a burst of gamma-rays, the highes