Spectroscopy for Cool Astronomical Objects

For cool stellar and substellar objects including brown dwarfs and exoplanets, atomic lines weaken and detailed elemental and isotopic abundances are often derived from molecular absorption features. We have embarked on a project to provide molecular line lists based on combining experimental observations for line positions and ab initio calculations for line strengths. So far we have results for MgH (A-X and B-X transitions)^1,2, C₂ (Swan system)^2,3, CN (red and violet systems)⁴, CP (A-X transition)⁵, NH (vibration-rotation bands) and OH (Meinel system). This talk will briefly describe the new line lists. Applications to the spectra of carbon-enhanced metal-poor stars, the K giant Arcturus, the metal-rich open cluster NGC 6791, the Sun and comets will be presented.