Kepler observations of the open cluster NGC 6819

Using photometry from the Kepler Input Catalogue, we determine the distance and age of NGC 6819 using several different methods. From isochrone fitting we find the age of the cluster to be about 2.5 Gyr. There are many different types of variables in the field, including eight delta Scuti stars, at least three gamma Dor variables and several eclipsing binaries of various types. We derive masses, radii and luminosities from 63 red giants with solar-like oscillations, including 28 stars with no previous measurements, from which we obtain an unreddened distance modulus of 12.20 +/- 0.06 mag. We measured rotation periods of 129 stars which showed variations attributable to starspots. There is a correlation between the rotation period and the colour which extends to stars with temperatures equivalent to late A-type. This implies that starspots are present in stars which are much hotter than previously supposed. We also discuss several eclipsing binaries and the variability of stars which are blue straggler candidates and discuss X-ray sources found in the cluster.