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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.

Two double-sun exoplanets have been discovered by the Kepler spacecraft, establishing a new class of ‘circumbinary’ exoplanets and suggesting that at least several million such systems exist in our Galaxy. Dual 'Suns' a common phenomenon The Kepler spacecraft's haul of newly discovered extrasolar planets continues to grow. Most Sun-like stars in the Milky Way are found in gravitationally bound pairs or binaries. The discovery of exoplanet Kepler-16 b showed that planets can exist in orbits around a binary, and now two further such 'circumbinary' planets have been found: Kepler-34 b and Kepler-35 b. Each is a low-density gas giant planet on an orbit closely aligned with that of its parent stars. Kepler-34 b orbits two Sun-like stars every 289 days, and Kepler-35 b orbits a pair of smaller stars every 131 days. The observed rate of circumbinary planets implies that 1% of close binary stars have giant planets in nearly coplanar orbits, equivalent to a population of at least several million such bodies in the Milky Way. Most Sun-like stars in the Galaxy reside in gravitationally bound pairs of stars 1 , 2 (binaries). Although long anticipated 3 , 4 , 5 , 6 , 7 , 8 , the existence of a ‘circumbinary planet’ orbiting such a pair of normal stars was not definitively established until the discovery 9 of the planet transiting (that is, passing in front of) Kepler-16. Questions remained, however, about the prevalence of circumbinary planets and their range of orbital and physical properties. Here we report two additional transiting circumbinary planets: Kepler-34 (AB)b and Kepler-35 (AB)b, referred to here as Kepler-34 b and Kepler-35 b, respectively. Each is a low-density gas-giant planet on an orbit closely aligned with that of its parent stars. Kepler-34 b orbits two Sun-like stars every 289 days, whereas Kepler-35 b orbits a pair of smaller stars (89% and 81% of the Sun’s mass) every 131 days. The planets experience large multi-periodic variations in incident stellar radiation arising from the orbital motion of the stars. The observed rate of circumbinary planets in our sample implies that more than ∼1% of close binary stars have giant planets in nearly coplanar orbits, yielding a Galactic population of at least several million.

We present the detection of five planets—Kepler-62b, c, d, e, and f—of size 1.31, 0.54, 1.95, 1.61 and 1.41 Earth radii (R ⊕ ), orbiting a K2V star at periods of 5.7, 12.4, 18.2, 122.4, and 267.3 days, respectively. The outermost planets, Kepler-62e and -62f, are super-Earth-size (1.25 R ⊕ < planet radius < 2.0 R ⊕ ) planets in the habitable zone of their host star, respectively receiving 1.2 ± 0.2 times and 0.41 ± 0.05 times the solar flux at Earth's orbit. Theoretical models of Kepler-62e and -62f for a stellar age of ~7 billion years suggest that both planets could be solid, either with a rocky composition or composed of mostly solid water in their bulk.

In this work, we quantify the performance of the Large Synoptic Survey Telescope (LSST) on the detection of eclipsing binaries. We use Kepler observed binaries to create a large sample of simulated pseudo-LSST binary light curves. From these light curves, we attempt to recover the known binary signal. The success rate of period recovery from the pseudo-LSST light curves is indicative of LSST's expected performance. Using an off-the-shelf analysis of variance routine, we successfully recover 71% of the targets in our sample. We examine how the binary period impacts recovery success and see that for periods longer than 10 days, the chance of successful binary recovery drops below 50%.

The increasing precision of astronomical observations of stars and stellar systems is gradually getting to a level where the use of slightly different values of the solar mass, radius, and luminosity, as well as different values of fundamental physical constants, can lead to measurable systematic differences in the determination of basic physical properties. An equivalent issue with an inconsistent value of the speed of light was resolved by adopting a nominal value that is constant and has no error associated with it. Analogously, we suggest that the systematic error in stellar parameters may be eliminated by (1) replacing the solar radius R ⊙ R ⊙ and luminosity L ⊙ L ⊙ by the nominal values that areby definitionexact and expressed in SI units: 1     R ⊙ N = 6.95508 × 10 8     m and 1     L ⊙ N = 3.846 × 10 26     W ; (2) computing stellar masses in terms of M ⊙ M ⊙ by noting that the measurement error of the product GM ⊙ G M ⊙ is 5 orders of magnitude smaller than the error in G G ; (3) computing stellar masses and temperatures in SI units by using the derived values M ⊙ 2010 = 1.988547 × 10 30     kg and T ⊙ 2010 = 5779.57     K ; and (4) clearly stating the reference for the values of the fundamental physical constants used. We discuss the need and demonstrate the advantages of such a paradigm shift.

The Kepler mission was designed to determine the frequency of Earth-sized planets in and near the habitable zone of Sun-like stars. The habitable zone is the region where planetary temperatures are suitable for water to exist on a planet's surface. During the first 6 weeks of observations, Kepler monitored 156,000 stars, and five new exoplanets with sizes between 0.37 and 1.6 Jupiter radii and orbital periods from 3.2 to 4.9 days were discovered. The density of the Neptune-sized Kepler-4b is similar to that of Neptune and GJ 436b, even though the irradiation level is 800,000 times higher. Kepler-7b is one of the lowest-density planets (approximately 0.17 gram per cubic centimeter) yet detected. Kepler-5b, -6b, and -8b confirm the existence of planets with densities lower than those predicted for gas giant planets.

Over 2500 eclipsing binaries were identified and characterized from the ultraprecise photometric data provided by the Kepler space telescope. Kepler is now beginning its second mission, K2, which is proving to again provide ultraprecise photometry for a large sample of eclipsing binary stars. In the 1951 light curves covering 12 days in the K2 engineering dataset, we have identified and determined the ephemerides for 31 candidate eclipsing binaries that demonstrate the capabilities for eclipsing binary science in the upcoming campaigns in K2. Of those, 20 are new discoveries. We describe both manual and automated approaches to harvesting the complete set of eclipsing binaries in the K2 data, provide identifications and details for the full set of candidate eclipsing binaries present in the engineering dataset, and discuss the prospects for application of eclipsing binary searches in the K2 mission.

K2 is the mission concept for a repurposed Kepler mission that uses two reaction wheels to maintain the satellite attitude and provide ~81 days of coverage for ten 105 deg2 fields along the ecliptic in the first 2.5 years of operation. We examine stellar populations based on the updated Besançon model of the Galaxy, comment on the general properties for the entire ecliptic plane, and provide stellar occurrence rates in the first six tentative K2 campaigns grouped by spectral type and luminosity class. For each campaign we distinguish between main the sequence stars and giants, and provide their density profile as a function of galactic latitude. We introduce the crowding metric that serves for optimized target selection across the campaigns. For all main sequence stars we compute the expected planetary occurrence rates for three planet sizes: 2–4, 4–8 and 8–32 R⊕ with orbital periods up to 50 days. In conjunction with Gaia and the upcoming Transiting Exoplanet Survey Satellite and Plato missions, K2 will become a gold mine for stellar and planetary astrophysics.

With the advent of high precision photometry from satellites such as Kepler and CoRoT, a whole new layer of interesting and astounding astronomical objects has been revealed: heartbeat stars are an example of such objects. Heartbeat stars are eccentric ellipsoidal variables that undergo strong tidal interactions when the stars are almost in contact at the time of closest approach. These interactions deform of the stars and cause a notable light curve variation in the form of a tidal pulse. A subset of these objects (~20%) show prominent tidally induced pulsations: pulsations forced by the binary orbit. We now have a fully functional code that models binary star features (using PHOEBE) and stellar pulsations simultaneously, enabling a complete and accurate heartbeat star model to be determined. In this paper we show the results of our new code, which uses emcee, a variant of mcmc, to generate a full set of stellar parameters. We further highlight the interesting features of KIC 8164262, including its tidally induced pulsations and resonantly locked pulsations.