17077

In the Kepler database lies an important and yet unexplored opportunity. The two d_commasuper-aperturesd_comma centered on the star clustersdoublePoint NGC 6791 and NGC 6819 - each containing several thousands stars - have been monitored almost continuously for over 4 yrs. If their stellar populations could be disentangled comma then these Kepler datasets would be of groundbreaking importance to assess planet occurrence rates in two uniquely large groups of homogeneous and coeval stars. We propose to obtain high-resolution HST images within these two super-aperture fields and use a well tested method (already proved successful) to combine Kepler lightcurves with HST source information. The unmatched HST image quality will provide a homogeneous comma complete comma and color-complete input list which will enable extracting Kepler light curves of all the objects. Furthermore comma HST allows us to obtain proper motions linked to the Gaia system and membership for all these stars. The combined data will provide about 25 comma 000 lightcurves - increasing the total Kepler sample by 15%! Based on the latest planet occurrence rates we expect to find over 70 transiting planets -- virgul40 in the solar-metallicity NGC 6819 comma and about 30-50 in the super-solar metallicity NGC 6791. Our program will greatly enhance the Kepler mission.s yield comma boost the number of known transiting planets comma and will allow a direct test of the planet occurrence rate-metallicity relationship in uniquely homogeneous and well-characterized samples. The proposed data will also enable many other investigations comma enhancing the legacy and the scientific impact of both the HST and the Kepler missions comma and target selections for future JWST and ARIEL follow-ups.