Using data obtained during the RATS-Kepler project, we identified one short-duration flare in a 1 h sequence of ground-based photometry of the dwarf star KIC 5474065. Observations made using Gran Telescopio Canarias show that it is a star with an M4V spectral type. Kepler observations made using 1 min sampling show that KIC 5474065 exhibits large-amplitude (δF/F > 0.4) optical flares which have a duration as short as 10 min. We compare the energy distribution of flares from KIC 5474065 with that of KIC 9726699, which has also been observed using 1-min sampling, and ground-based observations of other M dwarf stars in the literature. We discuss the possible implications these short-duration, relatively low-energy flares would have on the atmosphere of exoplanets orbiting in the habitable zone of these flare stars.

We outline the purpose, strategy and first results of a deep, high cadence, photometric survey of the Kepler field using the Isaac Newton Telescope on La Palma and the MDM 1.3m Telescope on Kitt Peak. Our goal was to identify sources located in the Kepler field of view which are variable on a timescale of a few mins to 1 hour. The astrophysically most interesting sources would then have been candidates for observation using Kepler using 1 min sampling. Our survey covered ∼42% of the Kepler field of view and we have obtained light curves for 7.1×10 5 objects in the range 13< g < 20.We have discovered more than 100 variable sources which have passed our two stage identification process. As a service to the wider community, we make our data products and cleaned CCD images available to download. We obtained Kepler data of 18 sources which we found to be variable using our survey and we give an overview of the currently available data here. These sources include a pulsating DA white dwarf, eleven δ Sct stars which have dominant pulsation periods in the range 24 min to 2.35 hrs, three contact binaries, and a cataclysmic variable (V363 Lyr). One of the δ Sct stars is in a contact binary.

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