PoSSO – Physics of SubStellar Objects

Abstract

A full understanding of the properties of substellar objects is one of the major challenges facing astrophysics. Since their discovery in 1995, we have discovered hundreds of brown dwarfs and extrasolar planets. While these discoveries have enabled important comparisons with theory, observational progress has been much more rapid than the theoretical understanding of cool atmospheres. The determination of mass, abundances, gravities and temperatures is not yet possible. The key problem is that substellar objects emit their observable radiation in the infrared region of the spectrum where our knowledge of atomic, molecular and line broadening data is poor. In order to understand these objects, and extra-solar planets increasing more like those our Solar System, we urge the wider physical chemistry community to engage in this exciting new field. Here we sketch an outline of the atoms, molecules and processes requiring study.