Gold formed from colliding stars

Where does gold come from?

The most abundant elements found in nature, such as oxygen and carbon, are seen throughout the universe, the products of exploding stars known as supernovas. Scientists agree that exploding stars produced most of the materials found on earth.

What about heavier elements such as gold and platinum? Normal stars don’t contain enough “stuff” to produce these heavy materials and their origins have been a mystery.

Now, a team from the Universities of Leicester, England, and Basel, Switzerland, led by Stephan Rosswog, has reported to the U.K. National Astronomy Meeting, sponsored by the Royal Astronomical Society, its theory about how heavy elements like gold and platinum were produced.

Rosswog’s team believes that the universe’s heaviest elements were formed by violent collisions of super-dense neutron stars. These stars are the burned-out centres of long dead stars with a mass a million times that of the Earth, condensed into an area about the size of New York, N.Y.

According to Rosswog, neutron stars are often found in pairs and collide when they are too close to each other. When a violent collision occurs, an enormous amount of energy is released and large quantities of gold and platinum are tossed into space.

Although a typical final explosion only takes a few milliseconds, modeling the event’s outcome took Rosswog and his team several weeks of calculations using the world’s fastest supercomputers. So intense were these explosions, that they produced enough energy to light the entire universe for the final few milliseconds of their existence.

When the stars finally collapsed, they formed so-called black holes, an area so dense that its gravitational pull does not allow even light to escape its grip.

The leftover ash, containing gold, platinum and other heavy metals, cooled down while continuing to fly deeper into outer space. Rosswog says that his calculations show that the amount of heavy elements that would have been formed by colliding neutron stars matches closely with the estimated amount of these elements currently in the Solar System.

“This is an incredible result,” Rosswog told an audience at the National Astronomy Meeting. “It’s exciting to think that gold in wedding rings was formed far away by colliding stars.”

–The preceding is from Gold News, a publication of the Washington, D.C.-based Gold Institute.