  We show that the Poynting-Robertson drag effect in an optically thin
advection-dominated accretion flow around active gravitating objects generates
strong azimuthal electric currents which give rise to astrophysically
significant magnetic fields. Although the mechanism is most effective in
accreting compact objects, it seems very promising to also account for the
generation of stellar dipolar fields during the late protostellar collapse
phase, when the star approaches the main sequence.
