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Mixing Along the Red Giant Branch: Where do we Stand? Corinne Charbonnel Abstract Low-mass stars exhibit, at all the stages of their evolution, signatures of mixing processes that require challenging modeling beyond the stellar standard theory. Here we focus on their abundance anomalies while they climb the red giant branch (RGB). We first compare the classical predictions for abundance variations due to the first dredge-up with observational data in various environments. We show how clear spectroscopic diagnostics probe the nucleosynthesis and the internal mixing mechanisms that drive RGB stars. Coherent data reveal in particular the existence of a non-standard and shallow mixing process that changes their surface abundances at the so-called RGB bump. We discuss the current understanding of the connection between this non-standard mixing and stellar rotation and the so-called Li-flash which is expected to occur at the very beginning of the extra-mixing episode. |