Measuring the ages of low-mass stars and brown dwarfs

Age is among the most elusive, yet important, fundamental properties of low–mass stars and brown dwarfs. M dwarfs have main‐sequence lifetimes that are estimated to be trillions of years, with little change in luminosity. In contrast, brown dwarfs cool and dim with time, resulting in a significant degeneracy between mass, age, and luminosity. Despite these inherent challenges, there have been recent efforts on both observational and theoretical fronts that may yield precise ages for low‐mass stars and brown dwarfs. We feature some current observational efforts focused on estimating ages of these objects as presented in our Cool Stars 17 splinter session. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)