Planet Hunters: A Transiting Circumbinary Planet in a Quadruple Star System

The data presented in this paper are the result of the efforts of the Planet Hunters volunteers, without whom this work would not have been possible. Their contributions are individually ac- knowledged at http://www.planethunters.org/authors. We also acknowledge the following list of individuals who flagged one or more of the transit events on Talk discussed in this paper before or after discovery of the planet: Hans Martin Schwengeler, Dr. Johann Sejpka, and Arvin Joseff Tan.

We report the discovery and confirmation of a transiting circumbinary planet (PH1) around KIC 4862625, an eclipsing binary in the Kepler field. The planet was discovered by volunteers searching the first six Quarters of publicly available Kepler data as part of the Planet Hunters citizen science project. Transits of the planet across the larger and brighter of the eclipsing stars are detectable by visual inspection every ~137 days, with seven transits identified in Quarters 1-11. The physical and orbital parameters of both the host stars and planet were obtained via a photometric-dynamical model, simultaneously fitting both the measured radial velocities and the Kepler light curve of KIC 4862625.The 6.18 $\pm$ 0.17 Earth radii planet orbits outside the 20-day orbit of an eclipsing binary consisting of an F dwarf (1.734 +/- 0.044 Solar radii, 1.528 +/- 0.087 Solar masses) and M dwarf (0.378 +/0 0.023 Solar radii, 0.408 +/- 0.024 solar masses). For the planet, we find an upper mass limit of 169 Earth masses(0.531 Jupiter masses) at the 99.7& confidence level. With a radius and mass less than that of Jupiter, PH1 is well within the planetary regime. Outside the planet’s orbit, at ~1000 AU, a previously unknown visual binary has been identified that is bound to the planetary system, making this the first known case of a quadruple star system with a transiting planet.

Megan E. Schwamb, Jerome A. Orosz, Joshua A. Carter, William F. Welsh, Debra A. Fischer, Guillermo Torres, Andrew W. Howard, Justin R. Crepp, William C. Keel, Chris J. Lintott, Nathan A. Kaib, Dirk Terrell, Robert Gagliano, Kian J. Jek, Michael Parrish, Arfon M. Smith, Stuart Lynn, Robert J. Simpson, Matthew J. Giguere, Kevin Schawinski (Submitted on 12 Oct 2012)

Comments: submitted to ApJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1210.3612v1 [astro-ph.EP]
Submission history
From: Megan Schwamb [view email]
[v1] Fri, 12 Oct 2012 19:50:18 GMT (7395kb)