We have used the results of 3D simulations of stellar carbon burning (Cristini et al. 2017, 2019) simulated on DiRAC systems to guide the development of a new prescription for convective boundary mixing in stellar evolution models. We applied the phenomenon of turbulent entrainment at convective boundaries, seen in the 3D simulations of convective shells, to the hydrogen-burning convective core of evolutionary models. Shown in the figure (Fig. 6 of Scott et al. MNRAS, 2021) are the evolutionary tracks, in terms of luminosity and temperature, of a selection of models from our grid. These include the previous standard of convective boundary mixing in our evolutionary code (blue curves) and new models with entrainment (red and purple dashed), with dots, plusses and crosses marking 90%, 95% and 99% of the hydrogen-burning lifetime respectively. We compared the coolest edge (rightmost extent) of these curves to both previous model grids using different amounts of mixing (Ekstrom et al. 2012, Brott et al. 2011, dotted lines) and observational constraints (Castro et al. 2014, dot-dashed line). The crosses on the entrainment model tracks, occurring at or near the cool edge of the tracks, follow a trend with mass which more closely follows the shape of the Castro et al. line than the previous model grids. This suggests that the physics included in the entrainment prescription could be used to reproduce observed features which are not seen in standard models. In future work, evolutionary models with improved convective boundary mixing physics will be used to initialise new 3D simulations of convection. For more details on this work, follow the weblink to Scott et al. 2021 article given below

Weblinks: 
MNRAS: https://academic.oup.com/mnras/advance-article-abstract/doi/10.1093/mnras/stab752/6169727
ArXiV: https://arxiv.org/abs/2103.06196