Unraveling Visible Spectra of S-type Stars: The f³Δ–a³Δ (<i>α</i> System) and e³Π–a³Δ (<i>β</i> System) Band Systems of ZrO

Abstract ZrO has many low-lying states, and its spectra are essential for the characterization of S-type stars. A high-resolution emission spectrum recorded with a Fourier transform spectrometer at the National Solar Observatory is used for the analysis. The 0–0 and 1–0 bands of the f 3 Δ–a 3 Δ system ( α system) and the 0–0 band of the e 3 Π–a 3 Δ system ( β system) have been rotationally analyzed using the modern spectral fitting program PGOPHER. New ab initio calculations of transition dipole moments have been performed to determine the band strengths. These band strengths are used to produce line lists that are suitable for the simulation of stellar spectra.