Astronomy Colloquium

Gyrochronology utilizes the spin-down of stars as a function of time as an indicator of stellar age. This technique has the potential to yield precise ages for large samples of stars, providing unprecedented chronological information for studies of the Milky Way and extrasolar planets. However, gyrochronology is in its adolescence: it has been tested under limited scenarios, but its weaknesses and limitations have hitherto been largely unexplored. With data from the Kepler mission we can address these gaps: we now have access to datasets of rotation periods for tens of thousands of stars, as well as independent asteroseismic ages and rotation periods for a few hundred old (main sequence) stars.  I will discuss my comparisons of theoretical rotation models to these Kepler data, which have yielded unexpected insights into the rotational lives of stars (and the Sun!), as well as a better understanding of the power and peril of gyrochronology as a tool.