INITIAL DATA RELEASE OF THE<i>KEPLER</i>-INT SURVEY

Abstract

This paper describes the first data release of the Kepler-INT Survey (KIS),\nthat covers a 116 deg2 region of the Cygnus and Lyra constellations. The Kepler\nfield is the target of the most intensive search for transiting planets to\ndate. Despite the fact that the Kepler mission provides superior time series\nphotometry, with an enormous impact on all areas of stellar variability, its\nfield lacks optical photometry complete to the confusion limit of the Kepler\ninstrument necessary for selecting various classes of targets. For this reason,\nwe follow the observing strategy and data reduction method used in the IPHAS\nand UVEX galactic plane surveys in order to produce a deep optical survey of\nthe Kepler field. This initial release concerns data taken between May and\nAugust 2011, using the Isaac Newton Telescope on the island of La Palma. Four\nbroadband filters were used, U, g, r, i, as well as one narrowband one, Halpha,\nreaching down to a 10-sigma limit of around 20th mag in the Vega system.\nObservations covering around 50 deg2, thus about half of the field, passed our\nquality control thresholds and constitute this first data release. We derive a\nglobal photometric calibration by placing the KIS magnitudes as close as\npossible to the Kepler Input Catalog (KIC) photometry. The initial data release\ncatalogue containing around 6 million sources from all the good photometric\nfields is available for download from the KIS webpage, as well as via MAST.\n