W. J. Maciel -
Abstract #176
MASS LOSS RATES OF LI-RICH AGB/RGB STARS FROM GAIA DATA
W. J. Maciel, R. D. D. Costa, Bol. SAB. 32, no. 1, 159 (2020) A recent determination of the mass loss rates of Li-rich AGB/RGB stars based on two independent methods suggests that their luminosities as well their mass loss rates are much lower than in the case of Li-poor stars, which form the majority of AGB/RGB stars. This is in contrast with some suggestions in the literature that the Li enrichment phenomenon may be associated with enhanced mass loss rates. In this work, we determine the mass loss rates of Li-rich AGB/RGB stars based on recent GAIA DR2 data. We consider two methods, the first one based on a correlation between the Li abundances and the stellar luminosity, and the second based on a correlation between the mass loss rate and some stellar parameters. These methods are applied to GAIA data, which include new results for some of the physical properties of the stars. As a result, some di erences are observed relative to the results based on earlier distances and luminosities, in particular a somewhat broader luminosity range is derived. It can be concluded that the new GAIA data confirm the previous results on the mass loss rates and luminosities of Li-rich stars, in the sense that both the average luminosities and mass loss rates of these stars are usually lower than the corresponding values of Li-poor objects. A comparison can then be made between the new results for Li-rich stars and the well determined mass loss rates and luminosities of Li-poor stars available in the literature.
