Name/Affiliation: Cecilia Marķa Guerra Olvera (Universidad de Guanajuato)
Revising the Wilson-Bappu effect
We use the versatile PHOENIX model atmosphere code, which includes a gravity-scaled chromosphere mode above the temperature minimum to model the Ca II K emission line profile for solar-type stars with different gravity. With models matching the line profile and chromospheric emission fluxes of relatively inactive stars, we are able to reproduce the Wilson-Bappu effect. We also quantify the apparent mean temperature minimum for an entirely inactive Sun by a model matching the basal Ca II flux, which was observed on several occasions in the extraordinay 2008/9 minimum.