Two Stars Collide: A Game Changer

Four times in the past 2 years, physicists working with mammoth gravitational-wave detectors have sensed something go bump in the dark, sending invisible ripples through spacetime. This past week, they announced the detection of a fifth such disturbance—but this time astronomers saw it, too, at every wavelength of light from gamma radiation to radio waves. Just as physicists had predicted, the unprecedented view of the cosmic cataclysm—in which two superdense neutron stars spiraled into each other—brought with it a cornucopia of insights, each one of them a major scientific advance. The super-dense stars crashed together 130 million light years away, spewing out precious metals and other heavy elements like platinum and uranium – and experts say the event has kickstarted a "new chapter in astrophysics" and confirmed theories about the origin of the mysterious neutron stars.  The combined observation with gravitational waves and light showed, as predicted, that so-called short gamma ray bursts, among the most powerful events in the cosmos, spring from neutron-star mergers. It demonstrated a hypothesized new type of stellar object called a kilonova because it shines thousands of times brighter than an ordinary nova. And it revealed that half the elements heavier than iron are produced, perhaps exclusively, in neutron-star death spirals.