Measurement of L-shell transitions in M-shell ions in the laboratory and identification in stellar coronae

Based on laboratory data from the Lawrence Livermore EBIT-I electron beam ion trap and calculations using the relativistic multi-reference Møller-Plesset (MRMP) perturbation theory approach, we identify L-shell transitions of M-shell iron ions in emission spectra of the nearby stars Capella and Procyon. These lines are weaker than the well known, prominent lines from Fe XVII. However, they need to be taken into account when modeling the spectra, especially of cool stars.