Heavy elements in metal-poor stars

Neutron star mergers have a fundamental role in the production of heavy elements, and the chemical traces of these events can be observed in the oldest stars of our Galaxy.

However, many of these elements can be observed exclusively in the UV. For this reason, CUBES will play a pivotal role in constraining the nucleosynthesis of neutron star mergers

CNO abundances

Abundances of C, N, and O are key inputs to studies of both stellar evolution and the chemical evolution of galaxies. Absorption lines of CN, NH and OH in the 300-400 nm region provide important diagnostics for estimates of CNO abundances.


Abundances of Be are a powerful diagnostic across a broad range of stellar science and the ground UV is our only opportunity to observe its spectral lines, with two Be II resonance lines at λλ3130, 3131. Four cases pertaining to Be were developed in the CUBES Phase A study, with a fifth added in the SPIE paper by Evans et al. (2018):

    • Using solar twins to constrain Li and Be depletion;

    • As a tracer of chemical mixing in low-mass stars;

    • Beryillium as a cosmochronometer;

    • Clues to the formation of globular clusters;

    • 7Be decay in novae as a potential channel for Li production.

Additional cases

Other galactic additional cases can be investigated with CUBES:

    • Exo-planet composition

    • Multiple populations in globular clusters

    • Precise metallicity measurements in metal-poor pulsating stars

More details are available in Paragraph 3.2 of the "Proposal for the VLT UV Spectrograph Phase A Study" (see DOCUMENT section of this website).