Lithium seven and its problem, thirty years later

 

Fabio Iocco

(Universidad Autónoma de Madrid)

 

In 1982, seminal work showed the puzzling behaviour of Lithium7 in low-metallicity, halo stars of our Galaxy. Those observations did in fact establish the paradigm of a Lithium7 abundance constant in stars spanning three orders of magnitude in metallicity. Since then, this finding has challenged our understanding of Stellar Atmospheres, Cosmological Nucleosynthesis and Stellar Formation environments, becoming known as the "Lithium Problem". Thirty years later, this problem is far from being solved, yet these decades of activity have brought new observations and theoretical advances in the field of cosmology, stellar evolution, stellar atmospheres, cosmic ray and primordial nucleosynthesis, bringing together fields traditionally apart. I will give an overview of the problem in an historical context, and examine the new progress made by all related fields.