Light Element Abundances

•7Li: Measured in high-resolution optical spectra of stars as an absorption feature.  Ideally look at old metal-poor stars with shallow convection zones (transport to the hot cores can destroy it).  Abundance estimated to be log[Li/H] = -9.80 +/- 0.16.  Again, interpretation more difficult than for deuterium.  (Also, cross sections for reaction making Li very uncertain.]