  We have studied Leo A - the isolated and extremely gas rich dwarf irregular
galaxy of very low stellar mass and metallicity. Ages of the stellar
populations in Leo A are ranging from ~10 Myr to ~10 Gyr. Here we report the
discovery of an old stellar halo and a sharp stellar edge. Also we find the
distribution of stars extending beyond the gaseous envelope of the galaxy.
Therefore, Leo A by its structure as well as stellar and gaseous content is
found to resemble massive disk galaxies. This implies that galaxies of very low
stellar mass are also able to develop complex structures, challenging
contemporary understanding of galaxy evolution.
