Related papers: Stellar proper motion and the timing of planetary …

We develop an analytic model for transit timing variations produced by orbital conjunctions between gravitationally interacting planets. If the planetary orbits have tight orbital spacing, which is a common case among the Kepler planets,…

A planet's orbital orientation relative to an observer's line of sight determines the chord length for a transiting planet, i.e., the projected distance a transiting planet travels across the stellar disc. For a given circular orbit, the…

The orbital parameters of the observed extrasolar planets differ strongly from those of our own solar system. The differences include planets with high masses, small semi-major axis and large eccentricities. We performed numerical…

Transit timing analysis may be an effective method of discovering additional bodies in extrasolar systems which harbour transiting exoplanets. The deviations from the Keplerian motion, caused by mutual gravitational interactions between…

While not detected yet, pairs of exoplanets in the 1:1 mean motion resonance probably exist. Low eccentricity, near-planar orbits, which in the comoving frame follow the horseshoe trajectories, are one of the possible stable configurations.…

The timing and duration of exoplanet transits has a dependency on observer position due to parallax. In the case of an Earth-bound observer with a 2 AU baseline the dependency is typically small and slightly beyond the limits of current…

We show that short-term perturbations among massive planets in multiple planet systems can result in radial velocity variations of the central star which differ substantially from velocity variations derived assuming the planets are…

Only a few exoplanets are known to orbit around fast rotating stars. One of them is XO-6b, which orbits an F5V-type star. Shortly after the discovery, we started multicolor photometric and radial-velocity follow-up observations of XO-6b,…

Transiting exoplanets in multi-planet systems have non-Keplerian orbits which can cause the times and durations of transits to vary. The theory and observations of transit timing variations (TTV) and transit duration variations (TDV) are…

We consider the effects of mutual transits by extrasolar planet-companion systems (in a true binary or a planet-satellite system) on light curves. We show that induced changes in light curves depend strongly on a ratio between a…

A planetary transit produces both a photometric signal and a spectroscopic signal. Precise observations of the transit light curve reveal the planetary radius and allow a search for timing anomalies caused by satellites or additional…

Planetary systems with multiple transiting planets are beneficial for understanding planet occurrence rates and system architectures. Although we have yet to find a solar system analogue, future surveys may detect multiple terrestrial…

The motion of the barycenter of the Solar System (SSB), the origin of the International Celestial Reference System, causes a directional displacement known as secular aberration. The secular aberration drift caused by the galactocentric…

We present photometry of HD 189733 during eight transits of its close-in giant planet, and out-of-transit photometry spanning two years. Using the transit photometry, we determine the stellar and planetary radii and the photometric…

Kepler will monitor enough stars that it is likely to detect single transits of planets with periods longer than the mission lifetime. We show that by combining the Kepler photometry of such transits with precise radial velocity (RV)…

When an extrasolar planet passes in front of its star (transits), its radius can be measured from the decrease in starlight and its orbital period from the time between transits. Multiple planets transiting the same star reveal more: period…

Extragalactic proper motions can reveal a variety of cosmological and local phenomena over a range of angular scales. These include observer-induced proper motions, such as the secular aberration drift caused by the solar acceleration about…

We considered the problem of stability for planets of finite mass in binary star systems. We selected a huge set of initial conditions for planetary orbits of the S-type, to perform high precision and very extended in time integrations. For…

Planetary transits provide a unique opportunity to investigate the surface distributions of star spots. Our aim is to determine if, with continuous observation (such as the data that will be provided by the Kepler mission), we can in…

The orbital motion of a binary system is characterized by various characteristic temporal intervals which, by definition, are different from each other: the draconitic, anomalistic and sidereal periods. They all coincide in the Keplerian…