Dust and Chromospheres in M warfs

摘要

Whilst impressive work has gone into modelling the spectra of M dwarfs over the past 10 years, there remain significant differences between the best model spectra and observations that indicate serious shortcomings in our understanding of M dwarf atmospheres. This contribution outlines the major observational differences and discusses the likelihood of dust opacity in the coolest M dwarfs and chromospheres in all M dwarfs as being explanations for the outstanding differences.