The late evolution of low-mass stars

Research Project, 2017 – 2020

The late evolution and death of stars is a fundamental research topic in astronomy. In the last stages of their lives, Sun-like stars evolve along the asymptotic giant branch (AGB), and contribute a significant fraction of heavy elements to the interstellar medium (ISM). In this research, I will determine the evolution of the mass loss from AGB stars during and after a thermal pulse. Thermal pulses are responsible for the chemical evolution of the star, the circumstellar envelope, and eventually the ISM. The amount of mass lost during the thermal pulse cycle is critical, as it limits the number of thermal pulses an AGB star experiences, and hence the yields to the ISM. I will combine observations from optical to submillimeter wavelengths to constrain the mass-loss history from AGB stars, and the amount of matter returned to the ISM . The observations will be used to model the evolution and interaction of the dust and gas using hydrodynamical and radiative transfer models to understand the physical processes of the mass loss and how this affects the evolution on the AGB. The proposed research will yield the most detailed view of the evolution of the mass loss throughout the thermal pulse cycle on the AGB. It will constrain critical aspects of late stellar evolution. The results will move current research beyond the state of the art in understanding the chemical evolution of stars, the ISM, and galaxies.