Pasadena, CA—The lightest few elements in the periodic table formed minutes after the Big Bang. Heavier chemical elements are created by stars, either from nuclear fusion in their interiors or in catastrophic explosions. However, scientists have disagreed for nearly 60 years about how the heaviest elements, such as gold and lead, are manufactured. New observations of a tiny galaxy discovered last year show that these heavy elements are likely left over from rare collisions between two neutron stars. The work is published by Nature.
The new galaxy, called Reticulum II because of its location in the southern constellation Reticulum, commonly known as The Net, is one of the smallest and closest to us known. Its proximity made it a tempting target for a team of astronomers including Carnegie’s Josh Simon, who have been studying the chemical content of nearby galaxies.