We show how the different assumptions on the transition time (the time lag between the superwind quenching at the AGB and the illumination of the Planetary Nebula [PN]) reflect into very different theoretical outcomes, both in the characteristics of the stellar remnants, and in the evolution of the nebular shells.
We use a Monte Carlo simulation of post-AGB stars with a set of assumptions on the transition time, to show the effect on the resulting location of the stars on the HR diagram, and on the derived core mass distributions.
We have also performed numerical simulations of the PN formation process, and investigated the effects of the transition time on the resulting PN structure. We found that the transition time determines not only the size of the PN shell, but also its dynamical evolution.
We show the important implications that the transition time has on the observable parameters during the PN stage.