Lithium

Lithium, the third element in the periodic table, holds a distinctive place in astronomical exploration due to its significant role in deciphering the universe's early stages and its influence on stellar evolution. During the primordial nucleosynthesis after the Big Bang, a fraction of lithium's abundance was synthesized, alongside hydrogen and helium, making it one of the few elements formed in substantial quantities in the universe's infancy. This primordial nature of lithium marks it as a crucial indicator in understanding the consistency between theoretical models of the early universe and the observed data.

Lithium Problem

Observations of lithium abundance in various astronomical objects, particularly in the oldest and metal-poor stars, provide essential insights into the early universe's chemical composition. Discrepancies between the predicted and observed lithium abundances in these ancient stars prompt refinements in our understanding of the processes that occurred during the universe's formative stages.

Stars

Throughout stellar evolution, the abundance of lithium within stars changes significantly. While younger stars tend to retain higher levels of lithium in their atmospheres, as stars age, internal processes and rising temperatures lead to lithium depletion through nuclear reactions. These observations of lithium depletion in stars of different ages and masses serve as vital tools for astronomers, shedding light on stellar lifecycles and internal mechanisms.

Stellar Evolution

Furthermore, the study of lithium abundance in stars is pivotal in understanding stellar models and formation. It acts as a diagnostic tool, offering insights into the mixing processes inside stars and contributing to the distinction between various stellar evolution theories. Moreover, in the realm of exoplanet studies, lithium's presence or absence in a star's spectrum significantly influences theories surrounding planetary formation and potential habitability of exoplanets orbiting those stars.

ISM

Lithium's presence extends beyond stars and encompasses the interstellar medium, where it exists primarily in gaseous form. Researching its abundance and distribution between stars contributes substantially to our understanding of the chemical composition and evolution of the interstellar medium.