Speaker
Description
Red giants and supergiants lose substantial fraction of their mass during their evolution and thus significantly contribute to the chemical enrichment of the interstellar medium. While the dust-driven wind coupled with pulsations can mostly explain the observed mass-loss rates of red giants on the asymptotic giant branch, this is not the case for red supergiants.
We obtained several epochs of Mira-type variable R Car and red supergiant VX Sgr, using spatially resolved near-infrared interferometry observations on VLTI-GRAVITY. We compare the observations with the state-of-the-art 1D and 3D models and archival data. This allows us to study regions close to stellar surface, where the mass-loss process is initiated, namely the continuum radius and the extended molecular layers, and also compare the structure and levitation of atmosphere between oxygen-rich Mira-type giants and red supergiants.