Old, partially-convective stars disagree with solar scalings.

Gyro-kinematic ages have unlocked a previously inaccessible domain over which rotational evolution models and gyrochronology can be rigorously tested. These ages push the boundaries of exploration to include a large population of old solar analogs and slowly rotating, fully convective stars. By using a combination of forward modeling techniques and empirical gyrochronology, we infer the required dynamo properties to explain spin down in these old stars. In the old field star domain, we find that standard spin down relationships cannot be extrapolated to old solar-like analogs and that standard assumptions about the magnetized wind do not hold. Our forward modelling favors a mass dependence in the dynamo scalings used to compute the magnetized winds. Pushing towards lower masses, we explore whether our model framework can reproduce the observed spin down of slowly rotating, fully convective stars. We use predictions from our best fit models to probe whether there is a smooth or abrupt transition between the dynamo properties of fully and partially convective stars.