Near-infrared and Visible Opacities of S-type Stars: The B 1 Π—X 1 Σ + Band System of ZrO

The ZrO B 1 Π—X 1 Σ + transition is an important opacity source in the near-infrared and optical spectrum of S-type stars. The 0–0, 0–1, 0–2, 1–0, 1–2, 1–3, 2–0, 2–1, 2–3, 2–4, 3–1, 3–4, and 4–2 bands of the 90 Zr 16 O B 1 Π—X 1 Σ + transition are reanalyzed using a high-temperature (2390 K) high-resolution (0.04 cm −1 ) emission spectrum collected at the National Solar Observatory (Kitt Peak). A modern spectroscopic analysis was performed using the PGOPHER program to provide updated spectroscopic constants and to produce a high-precision line list with line strengths based on an ab initio calculation of the transition dipole moment.