By Andrew Grant
The precise measurement of an exotic atom in the laboratory has refined scientists’ understanding of neutron stars, which are among the universe’s most extreme objects. The study, published January 22 in Physical Review Letters, could help scientists determine whether the crusts of neutron stars serve as the source of dozens of heavy elements such as zinc, silver and gold.
“One of the universe’s overriding mysteries is where heavy elements originate,” says James Lattimer, an astrophysicist at Stony Brook University in New York who was not involved in the study. “These mass measurements allow us to tune our equations so we can work toward settling the debate.”
Neutron stars are not actually stars at all. After a massive star explodes in a supernova, the remnant is a hot, dense ball about 20 kilometers across. It is made up of protons, electrons and lots of neutrons. That sphere packs in a mass larger than that of the sun, with a surface that one study estimates is 10 billion times as strong as steel. Under these extreme conditions, nuclei of atoms that are normally unstable can subsist in the neutron star’s outer layers.