  Since the discovery of the first exoplanets, those most adequate for life to
begin and evolve have been sought. Due to observational bias, however, most of
the discovered planets so far are gas giants, precluding their habitability.
However, if these hot Jupiters are located in the habitable zones of their host
stars, and if rocky moons orbit them, then these moons may be habitable. In
this work, we present a model for planetary transit simulation considering the
presence of moons and planetary rings around a planet. The moon's orbit is
considered to be circular and coplanar with the planetary orbit. The other
physical and orbital parameters of the star, planet, moon, and rings can be
adjusted in each simulation. It is possible to simulate as many successive
transits as desired. Since the presence of spots on the surface of the star may
produce a signal similar to that of the presence of a moon, our model also
allows for the inclusion of starspots. The result of the simulation is a light
curve with a planetary transit. White noise may also be added to the light
curves to produce curves similar to those obtained by the CoRoT and Kepler
space telescopes. The goal is to determine the criteria for detectability of
moons and/or ring systems using photometry. The results show that it is
possible to detect moons with radii as little as 1.3 R$_{\oplus}$ with CoRoT
and 0.3 R_{\oplus}$ with Kepler.
