Assume a gravitationally bound collection of stars, a galaxy or globular cluster say.Assume the stars are all old, none younger than 5 billion years, say.Assume a quite low average metallicity.How much dust would you expect there to be, still bound to the galaxy/GC?Specifically, are there any mechanisms which would deplete the object of a substantial proportion of its dust, as of the time of last star formation?Related question: where did all the dust that the Pop II stars which dominate ellipticals produced go?