Extended Data Fig. 4: Optical and NIR spectra of SN 2022jli around +210 days after discovery (optical spectrum taken with NOT/ALFOSC on 2022 November 25 and NIR spectrum taken with Magellan/FIRE on 2022 December 15).

The NIR spectrum has been scaled to match the flux of the optical spectrum in the overlapping region. The prominent features and the corresponding ions (or molecules) that likely contributed to the emission lines are marked. The spectrum in blue shows the mock spectrum of Fe II, Fe III and Ni II emission, and the vertical lines indicate emission from individual transitions which give relatively strong emission. The absolute strength of the mock spectrum is arbitrary, and the relative strength between different transitions for the same ion was calculated for a temperature of 10⁴ K, and an electron density of 10⁷cm⁻³.