Chinese scientists have discovered the most lithium-rich giant star ever known – with lithium abundance 3,000 times higher than normal – which could shed new light on the evolution of the universe. The star is in the direction of Ophiuchus, north side of the Galactic disk, with a distance of 4,500 light years to Earth, said researchers at National Astronomical Observatories of China (NAOC) and Chinese Academy of Sciences.
“The discovery of this star has largely increased the upper limit of the observed lithium abundance, and provides a potential explanation to the extremely lithium-rich case,” said Professor ZHAO Gang.
The findings, published in the journal Nature Astronomy, were realised with the help of The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) located in northern China. Lithium is considered one of the three elements synthesised in the Big Bang, together with Hydrogen and Helium. The abundance of the three elements was regarded as the strongest evidence of the Big Bang,which describes how the universe expanded from a very high-density and high-temperature state.
The evolution of lithium has been widely studied in modern astrophysics, however, a few giants were found to be lithium-rich in the past three decades. This makes the lithium study remarkably challenging, researchers said. Detailed information of the star was obtained by a follow-up observation from the Automated Planet Finder (APF) telescope at Lick Observatory, they said. Besides measuring the anomalously high lithium abundance, the research team also proposed a possible explanation to the lithium-rich phenomenon by the nuclear network simulation with the up-to-date atomic data as an input.