1996A&A...313..909G

Beryllium is a key element for constraining mixing processes taking place in the interiors of late-type dwarfs, and this paper investigates the use of neutral beryllium lines to obtain reliable abundances. The best candidate, among other Bei features, is the ⁹Bei λ2348.609Å resonance line. Its spectral location, well below the Earth's UV transmission limit, implies its observation with satellites (at the present time the Hubble Space Telescope -HST-). Synthetic spectra of this region, with different beryllium abundances, were computed for a cool star previously studied using the BeII λ3131.065Å line (which provided only an upper limit to its beryllium abundance). The low sensitivity shown by the feature associated with the Bei line to changes as large as three orders of magnitude in the beryllium abundance, the poor knowledge of the atomic and molecular line-data in the relevant spectral region, and the limited signal-to-noise ratios associated with the restricted exposure times of the HST prevent the use this line for abundance analysis purposes. This result is generally applicable to dwarf stars in the effective temperature range 4800-5800K. A detailed knowledge of the lines present in the spectral region considered would be essential for improving this situation. However, a similar improvement in the data for the lines surrounding the BeII λ 3131.065Å line (which is more isolated and can be observed from ground-based telescopes) would be probably much more useful.