  We studied the morphology of star formation in dwarf irregular galaxies and
found that, in general, this takes place on one side of a galaxy and far from
the center. This is mainly true for low surface brightness galaxies; in high
surface brightness dwarf irregulars the star formation tends to be more
centrally concentrated, as well as being more intense. We discuss possible star
formation triggers in dwarf irregular galaxies, and evaluate the reasons for
the peculiar distribution of star forming regions of these galaxies. Stochastic
star formation, interactions with external gas, and tidal interactions appear
to be ruled out as responsible for the asymmetric pattern of star formation. We
conclude that asymmetry of a dark matter halo or of an asymmetric underlying
stellar distribution may trigger an asymmetric pattern of star formation.
