TRIPLE-STAR CANDIDATES AMONG THE KEPLER BINARIES

• Main Authors: Deck, Katherine M. (Contributor), Borkovits, T. (Author), Carter, Joshua Adam (Author), El Mellah, I. (Author), Sanchis-Ojeda, R. (Contributor), Kalomeni, B. (Author), Rappaport, Saul A. (Contributor), Levine, Alan M. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), MIT Kavli Institute for Astrophysics and Space Research (Contributor)
• Format: Article
• Language: English
• Published: IOP Publishing, 2015-01-29T17:52:29Z.
• Subjects: Article
• Online Access: Get fulltext

We present the results of a search through the photometric database of Kepler eclipsing binaries looking for evidence of hierarchical triple-star systems. The presence of a third star orbiting the binary can be inferred from eclipse timing variations. We apply a simple algorithm in an automated determination of the eclipse times for all 2157 binaries. The "calculated" eclipse times, based on a constant period model, are subtracted from those observed. The resulting O - C (observed minus calculated times) curves are then visually inspected for periodicities in order to find triple-star candidates. After eliminating false positives due to the beat frequency between the ~[1 over 2] hr Kepler cadence and the binary period, 39 candidate triple systems were identified. The periodic O - C curves for these candidates were then fit for contributions from both the classical Roemer delay and so-called physical delay, in an attempt to extract a number of the system parameters of the triple. We discuss the limitations of the information that can be inferred from these O - C curves without further supplemental input, e.g., ground-based spectroscopy. Based on the limited range of orbital periods for the triple-star systems to which this search is sensitive, we can extrapolate to estimate that at least 20% of all close binaries have tertiary companions.
National Science Foundation (U.S.). Graduate Research Fellowship Program