The vast majority of low-metal halo dwarfs show a similar amount of Li ; this has been attributed to the Li that was produced in the Big Bang .
However , there are nine known halo stars with T > 5900 K and [ Fe/H ] < - 1.0 that are ultra-Li-deficient .
We have looked for Be in the very low metallicity star , G 186-26 at [ Fe/H ] = - 2.71 , which is one of the ultra-Li-deficient stars .
This star is also ultra-Be deficient .
Relative to Be in the Li-normal stars at [ Fe/H ] = - 2.7 , G 182-26 is down in Be by more than 0.8 dex .
Of two potential causes for the Li-deficiency – mass-transfer in a pre-blue straggler or extra rotationally-induced mixing in a star that was initially a very rapid rotator – the absence of Be favors the blue-straggler hypothesis , but the rotation model can not be ruled-out completely .