The Mass Loss Return from Stars to the Interstellar Medium

The final stages of stars such as our Sun are driven by mass loss from the star to the interstellar medium (ISM), and it is mainly in these mass flows that the dust grains which pervade the ISM are formed.  Thanks to its broad wavelength coverage in the infrared and its unprecedented angular resolution at these wavelengths, Herschel offers unprecedented opportunities to unravel the physical mechanism and temporal behavior of the outflows: velocity information throughout the wind identifies the acceleration region, mapping the dust shells reveals the importance of discrete high-mass-loss events.  In many objects the circumstellar structures are to a large extent shaped by interactions between the outflows and the pre-existing ISM, providing constraints also on the latter.