Kepler triples

The set of triples with outer orbital periods shorter than ~2000d is now sufficiently numerous for meaningful statistical analysis. We find that (i) there is a peak near i_m_=~40{deg} in the distribution of the triple versus inner binary mutual inclination angles that provides strong confirmation of the operation of Kozai-Lidov cycles with tidal friction; (ii) the median eccentricity of the third-body orbits is e_2_=0.35; (iii) there is a deficit of triple systems with binary periods <~1d and outer periods between ~50 and 200d which might help guide the refinement of theories of the formation and evolution of close binaries; and (iv) the substantial fraction of Kepler binaries which have third-body companions is consistent with a very large fraction of all binaries being part of triples.