Thursday 31 August at 3pm

ABSTRACT: "Measurements of the solar abundance ratio of carbon-12 to carbon-13 indicate that it is different from that of the local ISM; thus, it is supposed that this ratio has evolved since the formation of the solar system. It is well established that AGB stars are the dominatant source of material returned to the local interstellar medium (Jura, 1987). In previous work, Jane Greaves and Wayne Holland measured the carbon contributions of nearby *carbon-rich*, high mass-loss, asymptotic giant branch stars to the local ISM (using JCMT to observe their CO J=2->1 and 13CO J=2->1 lines) and were able to partly account for the evolving abundances. Continuing this work, Alex MacGillivray has been measuring the mass contribution of *oxygen-rich*, high mass-loss AGB stars to the local ISM. In his presentation, he will be giving a brief summary of his work and discussion of his results."