Princeton University/Institute for Advanced Study Planet/Exoplanet Discussion Group

The Monday Planet Lunch will be held weekly. We discuss recent papers from astro-ph and hear from the occasional exoplanet visitor. Graduate students are particularly encouraged to attend. The format will be informal and inclusive, spanning at a minimum exoplanets, the solar system, and astrobiology. Moreover, we plan on discussing multiple topics each time we meet, and not to tether a lunch to one organized presentation each sitting. The purpose is to foster wide-ranging and cross-fertilizing interaction and to keep the local community up to date on developments across the spectrum of associated activities. Joel Hartman and Tim Morton are the organizers. ABSTRACT: 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, the technique faces significant challenges, and must not be naively applied. I will discuss my ongoing investigation of the limitations of gyrochronology, and in particular, the insights we have gained thanks to the Kepler mission. We now have access to datasets of rotation periods for tens of thousands of stars, and independent asteroseismic ages for a few hundred stars. Our comparisons of theoretical predictions to Kepler data have yielded unexpected insights into the rotational lives of stars, as well as a better understanding of the power and peril of gyrochronology as a tool.