Joint Astrophysics Colloquium

Setting Stellar Chronometers: The PTF(+) Open Cluster Survey

Marcel Agüeros

Columbia University

While we have known for 40 years of the existence of a relation between a solar-mass star's age, rotation, and magnetic activity, observational limitations have hampered the assembly of uniform samples of rotation and activity measurements for stars spanning a wide range of ages and masses. We are still far from being able to describe fully the evolution of either rotation or activity for low-mass stars, or from being able to use rotation or activity measurements to estimate accurately the ages of isolated field stars. I will describe results from our efforts to assemble a complete sample of rotation and activity measurements for low-mass stars in six nearby open clusters ranging in age from ~100 Myr to ~3 Gyr. I will focus on our recent results for the benchmark clusters Praesepe and the Hyades, on new results for NGC 752, and on tests of models of rotational evolution that these data have enabled.