The lithium isotope ratio and beryllium in halo stars

The rare light elements — Li, Be, and B — have a unique and highly coupled history in the Universe. A coordinated analysis of their abundances in very low metallicity stars can help us understand the inner workings of stars and can constrain models of Galactic chemical evolution. We measure the Be abundances of nine stars and the Li isotopic ratio of ten stars. We find three stars with interesting Be abundances and three stars with detectable ⁶Li.