A Catalog of Periodic Variables in Open Clusters M35 and NGC 2158

Abstract

We present a catalog of 1,143 periodic variables, compiled from our image-subtracted photometric analysis of the K2 Campaign-0 super stamp. This super stamp is centered on the open clusters M35 and NGC 2158. Approximately 46% of our periodic variables were previously unreported. Of the catalog variables, we find that 331 are members of M35 and 56 are members of NGC 2158 ($P_{\mathrm{m}}>0.5$). Our catalog contains two new transiting exoplanet candidates, both of which orbit field stars. The smaller planet candidate has a radius of $0.35\pm 0.04{\mathrm{R}}_{\mathrm{J}}$ and orbits a K dwarf ($K_{\mathrm{p}}=15.4$ mag) with a transit depth of 2.9 millimag. The larger planet candidate has a radius of $0.72\pm 0.02{\mathrm{R}}_{\mathrm{J}}$ and orbits a late G type star ($K_{\mathrm{p}}=15.7$ mag) with a transit depth of 2.2 millimag. The larger planet candidate maybe an unresolved binary or a false alarm. Our catalog includes 44 eclipsing binaries, including ten new detections. Of the eclipsing binaries, one is an M35 member and five are NGC 2158 members. Our catalog contains a total of 1,097 non-transiting variable stars, including a field $\delta$ Cepheid exhibiting double mode pulsations, 561 rotational variables, and 251 pulsating variables (primarily $\gamma$ Doradus and $\delta$ Scuti types). The periods of our catalog sources range between 43 minutes to 24 days. The known ages of our reported cluster variables will facilitate investigations of a variety of stellar evolutionary processes.

arXiv comment34 pages, 24 figures

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