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Beryllium abundances in turn-off stars of globular clusters with the CUBES spectrograph


Globular clusters host multiple stellar populations that display star-to-star variation of light elements that are affected by hot hydrogen burning (e.g., He, C, N, O). Several scenarios have been suggested to explain these variations. Most involve multiple star formation episodes, where later generations are born from material contaminated by the nucleosynthetic products of the previous stellar generation(s). One difficulty in the modelling of such scenarios is knowing the extent to which processed and pristine material are mixed. In this context, beryllium abundances measured in turn-off stars of different generations can provide new information. Beryllium originates from cosmic-ray spallation and can only be destroyed inside stars. Beryllium abundances can thus directly measure the degree of pollution of the material that formed stars in globular clusters. Turn-off stars in globular clusters are however faint and such studies are beyond the capabilities of current instrumentation. In this work, we show the progress that the CUBES spectrograph will bring to this area. Our simulations indicate that CUBES will enable the detection of variations of about 0.6 dex in the Be abundances between stars from different generations, in several nearby globular clusters with turn-off magnitude down to V = 18 mag.

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Data availability

The datasets generated during the current study are available in the GitHub repository. A merged, re-normalised, re-sampled, and resolution homogenised version of the Kitt Peak Solar Atlas: A corrected line list with format compatible with Turbospectrum:


  1. Available at

  2. Depth of the weakest line with respect to the deepness of the strongest line produced

  3. Molecular line lists from these references already formatted for use with Turbospectrum can be downloaded at


  5. Available at:




  9. Computed assuming extinction \(A_V = 3.1 \times E(B-V)\)


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Use was made of the Simbad database, operated at the CDS, Strasbourg, France, and of NASA’s Astrophysics Data System Bibliographic Services. This work has made use of the VALD database, operated at Uppsala University, the Institute of Astronomy RAS in Moscow, and the University of Vienna.

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Correspondence to Riano E. Giribaldi.

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The authors declare that they have no conflict of interest. This work was supported by the National Science Centre, Poland, through project 2018/31/B/ST9/01469.

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The authors acknowledge support by the National Science Centre, Poland, through project 2018/31/B/ST9/01469.

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Giribaldi, R.E., Smiljanic, R. Beryllium abundances in turn-off stars of globular clusters with the CUBES spectrograph. Exp Astron (2022).

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  • Globular clusters
  • Stellar abundances
  • Stellar spectral lines