The effects of rotation-induced mixing on the properties of secondary clump stars

Uncertainties on the nature and efficiency of internal mixing processes in stars are becoming the dominant limitation to inferring accurate stellar ages. One particularly relevant uncertainty is that of the efficiency of additional mixing at the boundary of convective cores in the core hydrogen-burning phase. This project investigates a novel method of constraining such mixing processes, in particular those induced by rotation, by studying their imprint on the observed luminosity distribution and core-properties of low- to intermediate-mass core helium burning stars. Through the computation of single-age synthetic stellar populations using models that incorporate rotation-induced mixing, we have uncovered the appearance of extended red clumps within single-age clusters. The properties of these red clumps possess the potential to provide valuable insights into the efficiency of rotation-induced mixing processes, the origins of the observed extended red clumps and turn-offs, and to enhance the accuracy of age determinations. An initial assessment comparing the results with observations appears to support the plausibility of this scenario to some extent.