  Aims. We study the formation and water delivery of planets in the habitable
zone (HZ) around solar-type stars. In particular, we study different dynamical
environments that are defined by the most massive body in the system. Methods.
First of all, a semi-analytical model was used to define the mass of the
protoplanetary disks that produce each of the five dynamical scenarios of our
research. Then, we made use of the same semi-analytical model to describe the
evolution of embryos and planetesimals during the gaseous phase. Finally, we
carried out N-body simulations of planetary accretion in order to analyze the
formation and water delivery of planets in the HZ in the different dynamical
environments. Results. Water worlds are efficiently formed in the HZ in
different dynamical scenarios. In systems with a giant planet analog to Jupiter
or Saturn around the snow line, super-Earths tend to migrate into the HZ from
outside the snow line as a result of interactions with other embryos and
accrete water only during the gaseous phase. In systems without giant planets,
Earths and super-Earths with high water by mass contents can either be formed
in situ in the HZ or migrate into it from outer regions, and water can be
accreted during the gaseous phase and in collisions with water-rich embryos and
planetesimals. Conclusions. The formation of planets in the HZ with very high
water by mass contents seems to be a common process around Sun- like stars. Our
research suggests that such planets are still very efficiently produced in
different dynamical environments. Moreover, our study indicates that the
formation of planets in the HZ with masses and water contents similar to those
of Earth seems to be a rare process around solar-type stars in the systems
under consideration.
