 The stars were selected from the Kepler Input Catalog to have Teff, the effective temperature, between 5100 and 6000K (the solar value is 5750K) to find stars of similar spectral class to the Sun, and the surface gravity log g > 4.0 to eliminate sub-giants and giants.The spectral classes range from F8 to G8.The integration time was 30 min in the original study.