The heaviest natural elements on the periodic table such as gold, platinum, and uranium were forged during the mergers of binary neutron stars. Astronomers have previously estimated that tens of thousands of such binary neutron star mergers must have occurred throughout our Milky Way Galaxy during the past 10 billion years, sprinkling neutron-rich elements throughout the gas that eventually formed the next generation of stars and planets. By studying the composition of meteorites, astronomers now conclude that a single collision of neutron stars occurred shortly before and near to the formation of our solar system, producing a measurable fraction of the heavy elements here on Earth.
In 2017, an international group of astronomers and physicists excitedly reported the first simultaneous detection of light and gravitational waves from the same source–a merger of two neutron stars. In the world of astrophysics, Aug. 17, 2017, was a red-letter day. “This is a game-changer for astrophysics,” said UC Santa Barbara faculty member Andy Howell, who leads the supernova group at the Las Cumbres Observatory (LCO). “A hundred years after Einstein theorized gravitational waves, we’ve seen them and traced them back to their source to find an explosion with new physics of the kind we’ve only dreamed about.”
In the nearby Whirlpool galaxy and its companion galaxy, M51b, two supermassive black holes heat up and devour surrounding material. These two monsters should be the most luminous X-ray sources in sight, but a new study using observations from NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array) mission shows that a much smaller object is competing with the two behemoths.