2018ApJ...863...36H

Recent limitations in the TiO line list used in cross-correlation detection schemes have made the detection and quantification of TiO in exoplanetary atmospheres challenging. The quality of the line list appears to degrade at wavelengths shorter than 630 nm. The C³Δ-X³Δelectronic transition has strong rovibronic bands near 500 nm. In an effort to improve the line list, a spectrum of TiO in a furnace at 1950 K is analyzed, and the assigned lines of the C³Δ-X³Δtransition are fit with the \hatN² Hamiltonian in the molecular spectrum fitting software, PGOPHER. Several newly determined molecular constants are reported and the average error in fitting the line positions is 0.017 cm^–1 or ∼1 ppm relative error. The new line positions are expected to resolve any problems with cross-correlation templates near 500 nm.