Burbidge-Burbidge-Fowler-Hoyle 1957 r-process rapid-neutron-capture; site neutron-star-mergers Kasen 2017 GW170817 confirmation.
Burbidge-Burbidge-Fowler-Hoyle 1957 r-process rapid-neutron-capture; site neutron-star-mergers Kasen 2017 GW170817 confirmation.