The beryllium abundance in the very metal-poor halo star G64-12 from VLT/UVES observations

Abstract

We report on a newspectroscopic analysis of the very metal deficient star G64–12 ([Fe/H]=−3.3), aimed at determining, for the first time, its beryllium content. The spectra were observed during the Science Verification of UVES, the ESO VLT Ultraviolet and Visible Echelle Spectrograph. The high resolution (~48000) and high S/N (~130 per pixel) achieved at the wavelengths of the Be ii resonance doublet allowed an accurate determination of its abundance: log N(Be/H) = −13.10 ± 0.15 dex. The Be abundance is significantly higher than expected from previous measurements of Be in stars of similar metallicity (3D and NLTE corrections acting to make a slightly higher value than an LTE analysis). When compared to iron, the high [Be/Fe] ratio thus found may suggest a flattening in the beryllium evolutionary trend at the lowest metallicity end or the presence of dispersion at early epochs of galactic evolution. Based on observations taken during the Science Verification of UVES at the VLT/Kueyen telescope, European Southern Observatory, Paranal, Chile .