Lithium Production in Stars | 08 Jul 2020
Why in News
Recently, scientists from the Indian Institute of Astrophysics (IIA) have provided evidence for the first time that Lithium (Li) production is common among low mass Sun-like stars during their Helium (He) core burning phase.
- IIA is an autonomous institute of the Department of Science and Technology (DST), Government of India.
Key Points
- Findings of the Study:
- Scientists performed a large-scale systematic investigation of the ‘He-flash’ (on-set of He-ignition at the star's core via violent eruption), at the end of the star’s core hydrogen-burning phase.
- Hydrogen burning is the fusion of hydrogen nuclei into a helium nucleus.
- This He-flash has been identified as the source of Li production suggesting that all low-mass stars undergo Li production.
- Our Sun will reach this phase in about 6-7 billion years and will manufacture Li.
- The study challenges the long-held idea that stars only destroy lithium and indicates that there is some physical process missing in stellar theory.
- Earlier, it was believed that a vast majority of stars with a mass similar to that of the Sun destroy Li gradually over the course of their lives, via low-temperature nuclear burning.
- The study also suggests new limits (A(Li) > -0.9~dex) for classifying stars as Li-rich, which is 250 times below the threshold (A(Li) > 1.5~dex) used till now.
- Scientists performed a large-scale systematic investigation of the ‘He-flash’ (on-set of He-ignition at the star's core via violent eruption), at the end of the star’s core hydrogen-burning phase.
- Origin of Lithium:
- The origin of much of the Li can be traced to the Big-Bang that happened about 13.7 billion years ago.
- Over the course of time, Li content in the physical universe has increased by about a factor of four, which is meagre compared to the rest of the elements which grew about a million times.
- Stars are primary contributors to the significant enhancement of heavier elements through mass ejections and stellar explosions. Li, however, was thought to be an exception till now.
- Usage of Lithium:
- Lithium is a light inflammable metal which is mainly used in lithium-ion (Li-ion) batteries and has brought a transformation in modern communication devices and transportation.
- It is used in the manufacturing of aircrafts.
- It is also used in mental health. Lithium carbonate is a common treatment of bipolar disorder, helping to stabilize wild mood swings caused by the illness.