* Astronomy

Title: The architecture of the hierarchical triple star KOI 928 from eclipse timing variations seen in Kepler photometry
Authors: J. H. Steffen (1), S. N. Quinn (2), W. J. Borucki (3), E. Brugamyer (4), S. T. Bryson (3), L. A. Buchhave (5) W. D. Cochran (4), M. Endl (4), D. C. Fabrycky (6), E. B. Ford (7), M. J. Holman (2), J. Jenkins (3,8), D. Koch (3), D. W. Latham (2), P. MacQueen (4), F. Mullally (3,8), A. Prsa (9), D. Ragozzine (2), J. F. Rowe (3), D. T. Sanderfer (3), S. E. Seader (3,8) D. Short (10), A. Shporer (11), S. E. Thompson (3,8), G. Torres (2), J. D. Twicken (3,8) W. F. Welsh (10), G. Windmiller (10) ((1) Fermilab Center for Particle Astrophysics, Batavia (2) Harvard-Smithsonian Centre for Astrophysics, Cambridge (3) NASA Ames Research Centre, Moffett Field (4) McDonald Observatory, The University of Texas, Austin (5) Niels Bohr Institute, Copenhagen University, Copenhagen (6) Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz (7) Department of Astronomy, University of Florida, Gainesville (8) SETI Institute, Mountain View (9) Villanova University, Department of Astronomy and Astrophysics, Villanova (10) San Diego State University, San Diego (11) Las Cumbres Observatory Global Telescope, Goleta)

We present a hierarchical triple star system (KIC 9140402) where a low mass eclipsing binary orbits a more massive third star. The orbital period of the binary (4.98829 Days) is determined by the eclipse times seen in photometry from NASA's Kepler spacecraft. The periodically changing tidal field, due to the eccentric orbit of the binary about the tertiary, causes a change in the orbital period of the binary. The resulting eclipse timing variations provide insight into the dynamics and architecture of this system and allow the inference of the total mass of the binary (0.424 ±0.017 solar masses) and the orbital parameters of the binary about the central star.

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