Ages of open clusters NGC 6791 and NGC 6819 using the asterseismic isochrones fitting

Ning Gai, Department of Physics, Dezhou University, ning_gai@163.com

Abstract
Determining the age of clusters is normally done by fitting theoretical isochrones. Traditionally, we use the Luminosity-Effective Temperaure (L-Teff) diagram or color-magnitude diagram to find cluster ages. There are errors associated with such an age determination. The Kepler field-of-view contains four open clusters, including NGC 6791 and NGC 6819. Kepler is providing basic asteroseismic data for red-giant stars in these clusters, which allow ws to derive asteroseismic global oscillation parameters. These parameters, combined with conventional observations of luminosity and effective temperaure are being fitted the new isochrones. We find that we can determine the ages of clusters to a higher precision, and unlike traditonal isochrone fitting techniques, asteroseismic cluster ages are independent of the distance modulus.