ISO observations of AGB stars in the Small Magellanic Cloud

We used ISOCAM and ISOPHOT to observe the spectral energy distribution between 3.6 and 60 mum of AGB stars in the Small Magellanic Cloud detected by IRAs. CAM-CVF spectra are made which enable us to establish the carbon- or oxygen-rich nature of the stars. We are in the process of analysing this data using a radiative transfer model. This will provide us with accurate determinations of luminosity and mass loss rate. Combining the results on the SMC, LMC and Galaxy we hope to address the open question of the metallicity dependencies of the mass loss rate. This in turn is important in the ejection of matter by AGB stars into the interstellar medium.