Revised carbon 12C/13C isotope ratio of α Aurigae

The new measure of the carbon 12C/13C isotope ratio of the primary component of Capella, 17.8 ± 1.9, using high-resolution R ≈ 250 000 spectra obtained with PEPSI at both the Vatican Advanced Technology Telescope (VATT) and the Large Binocular Telescope (LBT) is significantly lower than the previous value of 27 ± 4 but now agrees better with the recent model prediction of 18.8-20.7.

The spectrum synthesis fitting.

Read more: Sablowski et al. 2019 A&A, 622, L11