Researchers of the Indian Institute of Astrophysics(IIA), Bangalore have discovered hundreds of Li-rich giant stars indicating that Lithium is being produced in the interstellar medium. They have also associated such Li enhancement with central He-burning stars, also known as red clump giants, thereby opening up new vistas in the evolution of the red giant stars.
Lithium(Li) is one of the three primordial elements, apart from Hydrogen(H) and Helium(He) that produced in the big bang nucleosynthesis(BBN). The present measurement of Li in the interstellar medium and very young stars is about 4 times more then the primordial value.
Indian Institute of Astrophysics(IIA) showed for the first time that the Li enhancement in giants is associated only with central He-burning stars, which are also known as red clump giants. This is an important discovery that will help to eliminate many proposed theories such as planet engulfment or nucleosynthesis during the red giant evolution in which helium at the center is not burning.
What is giant stars?
A giant star is a star with substantially larger radius and luminosity than a main-sequence (or dwarf) star of the same surface temperature. Giant stars have radii up to a few hundred times the Sun and luminosities between 10 and a few thousand times that of the Sun. Stars still more luminous than giants are referred to as supergiants and hypergiants.
What is Interstellar Medium?
In astronomy, the interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstellar space and blends smoothly into the surrounding intergalactic space.
About Indian Institute of Astrophysics(IIA):
The Indian Institute of Astrophysics (IIA), with its headquarters in Bengaluru (Karnataka state), is a National Research Institute of India. IIA conducts research primarily in the areas of astronomy, astrophysics and related subjects. It is widely recognised as a leading research center for astrophysics in India
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