Is beryllium in metal-poor stars of galactic or cosmological origin?

Standard Big Bang nucleosynthesis predicts a very small primordial abundance of beryllium. Observations of nine very metal-poor stars indicate a beryllium abundance roughly proportional to the oxygen abundance, a trend that can be explained in terms of galactic chemical evolution. Combining this rate of beryllium production with recent observations of boron and lithium in similar stars yields an upper limit to the primordial beryllium abundance several orders of magnitude greater than the cosmological prediction, a result that can be explained by cosmicray activity in the early Galaxy.