Abstract:
The initial mass function of zero and extremely-low metal poor stars are far from certain. Low mass stars may or may not form at zero metallicity because the critical metallicity for the formation of low mass stars is currently unknown? It is almost certain that the majority of the observed carbon-enhanced metal-poor stars were formed by mass transfer from a AGB companion. They could be important clues to deduce the initial mass of the companion with the observed abundances, provided that we understand the evolution of low-metallicity AGB stars. Current progress and problems of matching observation with stellar models will be discussed.
I will also briefly discuss an idea of the formation of Abell 58, a planetary nebula that could have undergone a nova-like eruption. The process involves mass transfer on a white dwarf in a common envelope system.
Coffee and tea will be served 20 minutes prior to the seminar.