Discovery of a Third Transiting Planet in the Kepler-47 Circumbinary System
Jerome A. Orosz, William F. Welsh, Nader Haghighipour, Billy Quarles, Donald R. Short, Sean M. Mills, Suman Satyal, Guillermo Torres, Eric Agol, Daniel C. Fabrycky, Daniel Jontof-Hutter, Gur Windmiller, Tobias W. A. Müller, Tobias C. Hinse, William D. Cochran, Michael Endl, Eric B. Ford, Tsevi Mazeh, Jack J. Lissauer
(Submitted on 15 Apr 2019)
Of the nine confirmed transiting circumbinary planet systems, only Kepler-47 is known to contain more than one planet. Kepler-47 b (the “inner planet”) has an orbital period of 49.5 days and a radius of about 3R⊕. Kepler-47 c (the “outer planet”) has an orbital period of 303.2 days and a radius of about 4.7R⊕. Here we report the discovery of a third planet, Kepler-47 d (the “middle planet”), which has an orbital period of 187.4 days and a radius of about 7R⊕. The presence of the middle planet allows us to place much better constraints on the masses of all three planets, where the 1σ ranges are less than 26M⊕, between 7−43M⊕, and between 2−5M⊕ for the inner, middle, and outer planets, respectively. The middle and outer planets have low bulk densities, with ρmiddle<0.68 g cm−3 and ρouter<0.26 g cm−3 at the 1σ level. The two outer planets are "tightly packed," assuming the nominal masses, meaning no other planet could stably orbit between them. All of the orbits have low eccentricities and are nearly coplanar, disfavoring violent scattering scenarios and suggesting gentle migration in the protoplanetary disk.
Comments: 68 pages, 30 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Journal reference: AJ, 157, 174 (2019)
DOI: 10.3847/1538-3881/ab0ca0
Cite as: arXiv:1904.07255 [astro-ph.EP] (or arXiv:1904.07255v1 [astro-ph.EP] for this version)
Submission history
From: Jerome A. Orosz
[v1] Mon, 15 Apr 2019 18:00:11 UTC (10,979 KB)
