Red supergiant star studies with CO5BOLD and Optim3D

摘要

We describe recent work focused towards a better understanding of redsupergiant stars using 3D radiative-hydrodynamics (RHD) simulations withCO5BOLD. A small number of simulations now exist that span up to seven years ofstellar time, at various numerical resolutions. Our discussion concentrates oninterferometric and spectroscopic observations. We point out a number ofproblems, in particular the line depth and line width that are not wellreproduced by simulations. The most recent introduction of a non-grey treatmentof the radiation field dramatically improved the match with observations,without solving all difficulties. We also review the newly revived effectivetemperature scale controversy, and argue that it will only be solved using 3DRHD models.