Discovery of variable stars in the field of the galactic open cluster NGC 7039

We report variable stars identified in the field of the Galactic open cluster, NGC 7039. In the fall/ winter of 2009, imaging photometry has been acquired, mainly in the R band, for eight open clusters using the 81 cm Tenagra telescope in Arizona. We present the results for our first target, NGC 7039. We have found 42 new variable stars and six suspected variable stars. Among the variable stars, there are 14 eclipsing binaries, including one RS Canum Venaticorum-type system, one RR Lyrae, two Cepheid, one β Cephei, three δ Scuti, eight pulsating like stars, five variable stars with periods longer than the observation window of 41 days, and eight irregular variable stars. Two contact binary systems could be members of NGC 7039 because of their loci in the color-magnitude diagram and their distance moduli close to that of the open cluster. One of the contact binary systems shows infrared excess in the (J - H) and (H - Ks) diagrams. It could have circumstellar dust. None of the pulsating stars belong to the open cluster.