New channels of single and binary evolution and nucleosynthesis

In this talk I will present our new findings on an exotic group of evolved objects: post-asymptotic giant branch (post-AGB) and post-red giant branch (post-RGB) stars. These objects bear the signatures of the entire morphological and nucleosynthetic changes that occur during and prior to the red giant evolutionary phases. Therefore, they provide excellent constraints for single and binary star evolution and nucleosynthesis. These objects have also revealed new evolutionary channels and AGB nucleosynthesis which is vital for understanding the complex chemical evolution of our Galaxy as well as external galaxies.