S-type Stars: LaO Line List for the B 2 Σ + –X 2 Σ + Band System

LaO bands are a characteristic feature in the spectrum of cool S-type stars. La is made primarily by the s -process during the asymptotic giant branch phase of stellar evolution. The B 2 Σ + –X 2 Σ + and A 2 Π–X 2 Σ + band systems can be used to determine the La abundances in cool S stars. The bands of the B 2 Σ + –X 2 Σ + with v ′ and v ′ ′ ≤ 5 have been rotationally analyzed from an emission spectrum from a carbon furnace. Line strengths are calculated using an ab initio transition dipole function, corrected using experimental lifetimes. We provide a line list for the B 2 Σ + –X 2 Σ + band system that can be used to determine La abundances.