Kepler-16: a transiting circumbinary planet.

Carl Sagan Center for the Study of Life in the Universe, SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043, USA.
Science (Impact Factor: 31.2). 09/2011; 333(6049):1602-6. DOI: 10.1126/science.1210923
Source: PubMed

ABSTRACT We report the detection of a planet whose orbit surrounds a pair of low-mass stars. Data from the Kepler spacecraft reveal transits of the planet across both stars, in addition to the mutual eclipses of the stars, giving precise constraints on the absolute dimensions of all three bodies. The planet is comparable to Saturn in mass and size and is on a nearly circular 229-day orbit around its two parent stars. The eclipsing stars are 20 and 69% as massive as the Sun and have an eccentric 41-day orbit. The motions of all three bodies are confined to within 0.5° of a single plane, suggesting that the planet formed within a circumbinary disk.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The planet Kepler-16b is known to follow a circumbinary orbit around a double system of two main-sequence stars. We construct stability diagrams in the "pericentric distance - eccentricity" plane, which show that Kepler-16b is in a hazardous vicinity to the chaos domain - just between the instability "teeth" in the space of orbital parameters. Kepler-16b survives, because it is close to the half-integer 11/2 orbital resonance with the central binary. The neighbouring resonance cells are vacant, because they are "purged" by Kepler-16b, due to overlap of first-order resonances with the planet.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We report the detection of Kepler-47, a system consisting of two planets orbiting around an eclipsing pair of stars. The inner and outer planets have radii 3.0 and 4.6 times that of Earth, respectively. The binary star consists of a Sun-like star and a companion roughly one-third its size, orbiting each other every 7.45 days. With an orbital period of 49.5 days, 18 transits of the inner planet have been observed, allowing a detailed characterization of its orbit and those of the stars. The outer planet's orbital period is 303.2 days, and although the planet is not Earth-like, it resides within the classical "habitable zone," where liquid water could exist on an Earth-like planet. With its two known planets, Kepler-47 establishes that close binary stars can host complete planetary systems.
    Science 08/2012; 337(6101):1511-4. · 31.20 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The increasing number and variety of extrasolar planets illustrates the importance of characterizing planetary perturbations. Planetary orbits are typically described by physically intuitive orbital elements. Here, we explicitly express the equations of motion of the unaveraged perturbed two-body problem in terms of planetary orbital elements by using a generalized form of Gauss' equations. We consider a varied set of position and velocity-dependent perturbations, and also derive relevant specific cases of the equations: when they are averaged over fast variables (the "adiabatic" approximation), and in the prograde and retrograde planar cases. In each instance, we delineate the properties of the equations. As brief demonstrations of potential applications, we consider the effect of Galactic tides. We measure the effect on the widest-known exoplanet orbit, Sedna-like objects, and distant scattered disk objects, particularly with regard to where the adiabatic approximation breaks down. The Mathematica code which can help derive the equations is freely available upon request.
    Celestial Mechanics and Dynamical Astronomy 10/2012; 115(2). · 2.32 Impact Factor

Full-text (2 Sources)

Available from
May 30, 2014