This is how neutron stars make gold

A neutron star corresponds to the final stage of the life of a massive star. It is an unusually dense body. It is as if all of humanity is concentrated in a sugar cube. We know that when two neutron stars collide, some of the most extreme conditions in our universe are created. Basic conditions for the formation of heavy elements such as uranium or gold.

Neutron star collision scenario

In 2017, astronomers were able to record signs of a collision between neutron stars for the first time. Gravitational waves and gamma-ray bursts are all accompanied by flashes of light. Event GW170817 occurred about 130 million light-years from our Earth. By combining all this data with the results of laboratory experiments in the new modeling tool, researchers from the Max Planck Institute for Gravitational Physics and the University of Potsdam (Germany) were able to reproduce most of the details of what happened at that time. They publish it in the magazine Nature Communications.

On the basis of recorded gravitational waves, they first described the final orbits of the two neutron stars. Trajectories that led them to collide, ejecting heavy elements into space. Some of these radioactive elements then decayed into more stable elements like gold, raising the temperature and generating a fireworks display of electromagnetic signals ranging from infrared to ultraviolet to visible. The gamma-ray burst, also caused by the collision between neutron stars, ejected even more material. The interaction of this material with the surrounding environment emits X-rays and radio waves.

Study other collisions to better understand the composition of gold

Upgraded gravitational wave detectors were launched in the fourth observing campaign. Astronomers hope to uncover other neutron star collisions that can be studied using this tool they developed.