Ellipsoidal Variability in the OGLE Planetary Transit Candidates

We analyze the photometry of 117 OGLE stars with periodic transit events forthe presence of ellipsoidal light variations, which indicate the presence ofmassive companions. We find that ~50% of objects may have stellar companions,mostly among the short period systems. In our Table 1 we identify a coefficientof ellipsoidal variability for each star, a_{c2}, which can be used to selectprime candidates for planetary searches. There is a prospect of improving theanalysis, and the systems with smaller ellipsoidal variability will beidentified, when the correlations in the OGLE photometry are corrected for inthe future, thereby providing a cleaner list of systems with possible planets.Comment: 22 pages, 9 figures, discussion enhanced, accepted by Ap