Transiting exoplanet candidates from<i>K2</i>Campaigns 5 and 6

Abstract

We introduce a new transit search and vetting pipeline for observations from\nthe K2 mission, and present the candidate transiting planets identified by this\npipeline out of the targets in Campaigns 5 and 6. Our pipeline uses the\nGaussian Process-based K2SC code to correct for the K2 pointing systematics and\nsimultaneously model stellar variability. The systematics-corrected,\nvariability-detrended light curves are searched for transits with the Box Least\nSquares method, and a period-dependent detection threshold is used to generate\na preliminary candidate list. Two or three individuals vet each candidate\nmanually to produce the final candidate list, using a set of\nautomatically-generated transit fits and assorted diagnostic tests to inform\nthe vetting. We detect 147 single-planet system candidates and 5 multi-planet\nsystems, independently recovering the previously-published hot~Jupiters EPIC\n212110888b, WASP-55b (EPIC 212300977b) and Qatar-2b (EPIC 212756297b). We also\nreport the outcome of reconnaissance spectroscopy carried out for all\ncandidates with Kepler magnitude Kp &lt; 13, identifying 12 targets as likely\nfalse positives. We compare our results to those of other K2 transit search\npipelines, noting that ours performs particularly well for variable and/or\nactive stars, but that the results are very similar overall. All the light\ncurves and code used in the transit search and vetting process are publicly\navailable, as are the follow-up spectra.\n