KEPLER-413B: A SLIGHTLY MISALIGNED, NEPTUNE-SIZE TRANSITING CIRCUMBINARY PLANET

We report the discovery of a transiting, R sub(p) = 4.347 + or - 0.099R sub([+ in circle]), circumbinary planet (CBP) orbiting the Kepler K + M eclipsing binary (EB) system KIC 12351927 (Kepler-413) every ~66 days on an eccentric orbit with a sub(p) = 0.355+ or -0.002 AU, e sub(p) = 0.118+ or -0.002. The orbital plane of the EB is slightly inclined to the line of sight (i sub(EB) = 87[degrees].33 + or - 0[degrees].06), while that of the planet is inclined by ~2[degrees].5 to the binary plane at the reference epoch. Orbital precession with a period of ~11 yr causes the inclination of the latter to the sky plane to continuously change. As a result, the planet often fails to transit the primary star at inferior conjunction, causing stretches of hundreds of days with no transits (corresponding to multiple planetary orbital periods).