This Hubble Space Telescope image shows stars at various stages of their lives, from young red-hot stars to cooler red giants. Our study focused on the lithium content of red giant stars Credit: NASA, ESA, and T. Brown (STScI)
Lithium is becoming common in our daily life. It is the key ingredient in the batteries in our mobile phones and electric vehicles, but have you ever wondered where it comes from?
A new study led by Professor Zhao Gang and Dr. Yerra Bharat Kumar of the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) provides a new understanding of how lithium is produced and how it is destroyed.
The study was published in Astronomy of nature July 6.
The researchers studied the lithium content of hundreds of thousands of Sun-like stars to understand how this element changes over time in stars.
“Lithium is a pretty special element,” said Dr. Yerra Bharat Kumar, the study’s first author. “Our study challenges the idea that stars like the Sun only destroy lithium through their lives.”
“Our observations show that they actually create it later in their lives, after they have swollen into red giants. This means that the Sun itself will also make lithium in the future,” he said.
Lithium is one of the three elements produced in the Big Bang. It is very easily destroyed within stars where it is too hot to survive, so the lithium content generally decreases as stars age.
Since lithium is such a sensitive element, it is very useful for understanding stars. It acts as a marker of what happens inside the stars.
To better understand this sensitive element, the researchers used data from a large Chinese stellar spectroscopic study based on The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). The survey is currently building a database of the spectra of ten million stars.
This study also used data from the Australian stellar survey known as GALAH.
“By looking at the starlight, we can determine what the stars are made of,” said Dr. Yerra Bharat Kumar. “The models show that our current theories of how stars evolve do not predict this lithium production at all. Therefore, the study has created a tension between observations and theory.”
“Our findings will help us better understand and model Sun-like stars,” said Professor Zhao Gang, corresponding co-author of this study.
“Since newly created lithium will end up being ejected from the star in stellar winds, it will also help us understand how these stars contribute to the lithium content of our galaxy and to planets like Earth,” said Professor Zhao.
Astronomers discover most of the lithium-rich giants in the galaxy with LAMOST
Yerra Bharat Kumar et al, Discovery of the ubiquitous production of lithium in low-mass stars, Astronomy of nature (2020). DOI: 10.1038 / s41550-020-1139-7
Provided by the Chinese Academy of Sciences
Citation: Study reveals secret life of lithium in Sun-like stars (2020, July 6) retrieved on July 7, 2020 from https://phys.org/news/2020-07-reveals-secret-life-lithium- sun-like.html
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