A odd glow from a short gamma-ray burst (GRB) in a galaxy 3.9 billion light years away in theconstellation Leo on June 3 by NASA’s Swift space telescope hints that all of Earth's gold is the product of collisions between dead neutron stars. The gamma-ray explosion resulting from dead stars crashing together 24 sextillion miles away created an initial burst that lasted only only two-tenths of a second. But the infrared glow that lingered around the area afterward suggests that gold may have been among the elements thrown out in the collision. After comparing their observations using the powerful ESO telescope in Chile and the Hubble Space Telescope with theoretical models, the astronomers concluded that they were seeing the afterglow from a huge quantity of heavy metals formed in the collision.
The image above is a first direct look, in visible light, at a lone neutron star (RX J185635-3754). Produced with the Wide-Field Planetary Camera 2, Hubble Space Telescope.Current observation and theories say that the heavy elements of the periodic table, such as gold, platinum, lead and uranium, had their origin in supernova explosions, but failed to explain the volume of gold in our solar system. About a decade ago, researchers in Europe used supercomputers to test their theory that heavier metals like gold and platinum could be formed from the massive explosion that occurs when two ultra-dense dead neutron stars collide.
It has long been understood that Earth’s elements are of cosmic origin. Carbon and oxygen atoms in our bodies, for example, come from the interior of stars, where they were formed under high pressure and heat. They were later spewed into the universe in supernova explosions.
A single neutron star might be roughly the size of Manhattan, but contain as much mass as our sun, or more, with all of it crammed together by the force of gravity until even the atoms have collapsed, leaving the object with the density of an atomic nucleus. A teaspoon of neutron-star mass would weigh, on Earth, about 5 billion tons.
“We are all star stuff, and our jewelry is colliding-star stuff,” said Edo Berger, an astronomer who led the research at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. In the Milky Way a neutron-star collision is likely to happen about once every 100,000 years, Berger said. But the universe is big, containing many billions of galaxies, and so astronomers doing an all-sky survey will occasionally see one of these rare GRBs.
The Daily Galaxy via CfA