The depletion of carbon by extra mixing in metal-poor giants
There is an apparent dichotomy between the metal-poor ([Fe/H] ≤ -2) yet carbon-normal giants and their carbon-rich counterparts. The former undergo significant depletion of carbon on the red giant branch after they have undergone first dredge-up, whereas the latter do not appear to experience significant depletion. We investigate this in the context that the extra mixing occurs via the thermohalin
