Robert Farmer

Carbon is essential for life, yet there remains uncertainties in when and where it is formed. The two main sources are massive stars and AGB stars. In this talk I will discuss how massive stars produce and eject carbon into the Universe. In single stars this can occur through wind mass loss and the ejection of the envelope in a core collapse supernovae. Using the MESA stellar evolution code I will show how the carbon yields vary between these different processes and thus varies over time. I will show how carbon yields vary between single and binary stars evolved up to core collapse as well their post supernovae explosive yields. I will discuss the role that a star being in a binary has on the production of carbon. Massive stars in binaries can be stripped by the companion, leading to additional mass loss. However I will show that it is the change in the core structure of the star, due to mass loss, that leads to an increase in the carbon yield and not the additional mass lost by itself.