  The structure of eta-nucleus bound systems (eta mesic nuclei) is investigated
as one of the tools to study in-medium properties of the N(1535) (N*)
resonance. We show that, as a general consequence, the eta-nucleus potential
has a repulsive core at the nuclear center with an attractive part at the
nuclear surface, if sufficient reduction of the mass difference of N and N*
stems from the in-medium effects to N*. The (d,3He) spectra are evaluated for
the formation of these bound states to investigate the experimental
feasibility.
