Unlocking stellar ages with Gaia: prospects for galactic archaeology and exoplanet populations
The processes behind the formation of the galaxy and the formation of exoplanets are two elusive and complicated topics in astrophysics connected by a common theme: stellar ages. Main sequence stars comprise the majority of our galaxy but unfortunately their ages are notoriously difficult to measure. Their positions on the HR diagram don't change significantly during their hydrogen burning lifetimes, a fact that is convenient for life on Earth but inconvenient for galactic archaeologists. Now, due to the abundance of rotation periods for MS stars provided by Kepler and to-be provided by TESS, LSST and Wfirst, rotation periods are the most readily available, precise age indicators. Rotation-dating works well for young stars but a question mark still hangs over its accuracy for stars older than the Sun. Gaia provides dynamical ages for thousands of stars, which can be used to test, and even calibrate the age-rotation relations. I will present methods for inferring! Probabilistic rotation periods from light curves and discuss a new age model that uses both rotation periods and dynamical information, applicable to the millions of stars ultimately observed by Gaia, Kepler, TESS, LSST and Wfirst.