  Abundance measurements of the light elements lithium, beryllium, and boron
are playing an increasingly important role in the study of stellar physics.
Because these elements are easily destroyed in stars at temperatures 2--4
million K, the abundances in the surface convective zone are diagnostics of the
star's internal workings. Standard stellar models cannot explain depletion
patterns observed in low mass stars, and so are not accounting for all the
relevant physical processes. These processes have important implications for
stellar evolution and primordial lithium production in big bang
nucleosynthesis. Because beryllium is destroyed at slightly higher temperatures
than lithium, observations of both light elements can differentiate between the
various proposed depletion mechanisms. Unfortunately, the reaction rate for the
main destruction channel, 9Be(p,alpha)6Li, is uncertain. A level in the
compound nucleus 10B is only 25.7 keV below the reaction's energetic threshold.
The angular momentum and parity of this level are not well known; current
estimates indicate that the resonance entrance channel is either s- or d-wave.
We show that an s-wave resonance can easily increase the reaction rate by an
order of magnitude at temperatures of approximately 4 million K. Observations
of sub-solar mass stars can constrain the strength of the resonance, as can
experimental measurements at lab energies lower than 30 keV.
