The Pulsation of M-type Miras: Multi-Epoch ISO-SWS Observations and Dynamical Models

Abstract

AbstractWe present time series of observed and synthetic ISO-SWS spectra of oxygen-rich Mira variables covering the wavelength range between 2.36 and 7.75 μm. The calculations are based on new dynamical models, which have been computed with a non-grey radiative transfer taking into account all relevant molecular opacities. It turns out that many features in the ISO spectra of cool long period variables which could not be reproduced within the framework of classical hydrostatic model atmospheres nor with grey dynamical calculations can now be understood without any additional assumptions. This is especially true for the water bands, which dominate the opacity in the infrared range of M-type Miras.