How elements are made beyond the stars
Tim Wogan looks at what recent astronomical discoveries have added to our understanding of stellar nucleosynthesis, and the mysteries that remain
On 17 August 2017, tiny, sequential fluctuations in the relative arm lengths of the two detectors of the Laser Interferometer Gravitational Wave Observatory signalled passing gravitational waves. This was the ninth time such oscillations in the fabric of spacetime itself had been recorded since gravitational waves had first been seen in September 2015. Unlike previous detections from merging black holes, however, which had otherwise been invisible, this event from merging neutron stars had an accompanying light show. What astronomers observed in the next few days and weeks would revolutionise scientists’ understanding of the origins of heavy nuclei such as gold, uranium and plutonium. Four years later much still remains shrouded in mystery, but many researchers hope clarity is not too far away.