Published online by Cambridge University Press: 26 February 2009
All stars end through a phase where they form copious amounts ofdust either in a stellar outflow or following explosive events. The mostefficient dust factories seem to be stars that evolve through the Red Giantstage and form for several 105 yrs, dust in a cool stellar wind. The dustreturned by them triggers the interstellar dust cycle and therefore is vital forthe matter cycling in space. We discuss the theoretical basis for calculatingthe dust production by such stars. First, some elements of the theory of chemicalequilibrium condensation calculations are presented and it is then discussed howthe concept of activities can be used to also study non-equilibrium condensation.Then we discuss how dust particle growth in stellar winds can be calculated andwhich kind of input data are required for such calculations. Finally someresults for dust production by AGB stars are discussed.