Lithium is one of the few elements produced during the Big Bang, and then it is mostly destroyed in stars. The primordial lithium abundance have been estimated by means of: a) Big Bang nucleosynthesis models combined with WMAP observations; and b) lithium abundances in old, pop II stars, more precisely those in the so called Spite plateau. The two estimations differ of a factor two.
This factor, when compared to the enormous range that lithium abundance in Galactic objects spans (two order of magnitude from the Sun to the interstellar medium) is widely considered an important confirmation that both cosmological standard models and stellar abundance determinations have sound basis. And yet an explanation has to be found for it: is the Big Bang nucleosynthesis model to be corrected, or is the atmospheric content of Spite plateau stars different from the primordial one? Both hypothesis have been suggested in the literature. Who is right? After extensively reviewing this topic, I will speak about the role of observations in open clusters in solving the dilemma.
2008 January 30, 13:30
Centro de Astrofísica da Universidade do Porto (Auditorium)
Rua das Estrelas, 4150-762 Porto