Astronomical Institute 'Anton Pannekoek' University of Amsterdam Kruislaan 403 NL-1098 SJ Amsterdam The Netherlands
The ISO satellite has opened the infrared spectral region for high quality spectroscopy and imaging of the photospheres and outflows of Asymptotic Giant Branch (AGB) stars and their descendants, the post-AGB stars and Planetary Nebulae. The impact of ISO on this field of research already is overwhelming, and the study of ISO data will undoubtedly reveal many more surprises in the future. The high-quality spectra covering the 2.4-200 micron wavelength region taken with SWS and LWS reveal an incredible wealth of gas-phase molecular absorption and emission bands, many for the first time observed with ISO; these data shed new light on the atmospheres and cool outer layers of the extended atmospheres of AGB stars. These spectra also show a remarkable structure in the emission from solid state particles, both for the oxygen-rich stars as well as the carbon-rich objects.
Imaging and photometry of AGB and post-AGB stars with ISOCAM and ISOPHOT give direct information about the recent mass loss history of the star and the geometry of the mass loss.