ABSTRACT Planet–planet (P–P) scattering is a leading dynamical mechanism invoked to explain the present orbital distribution of exoplanets. Many stars belong binary systems; therefore, it important understand how this works in presence companion star. We focus on systems three planets orbiting primary star and estimate time-scale for instability, finding that scales with Keplerian period have s...

Atomic hydrogen escaping from the extrasolar giant planet HD209458b provides the largest observational signature ever detected for an extrasolar planet atmosphere. In fact, the upper atmosphere of this planet is evaporating. Observational evidences and interpretations coming from various models are reviewed. Implications for exoplanetology are discussed.

Context. A well-known bottleneck for the core-accretion model of giant-planet formation is the loss of the cores into the star by Type-I migration, due to the tidal interactions with the gas disk. It has been shown that a steep surface-density gradient in the disk, such as the one expected at the boundary between an active and a dead zone, acts as a planet trap and prevents isolated cores from ...

In this Letter, we measure the full orbital architecture of two-planet system around nearby K0 dwarf 14 Herculis. Her (HD 145675, HIP 79248) is a middle-aged ($4.6^{+3.8}_{-1.3}$ Gyr) star with two eccentric giant planets identified in literature from radial velocity (RV) variability and long-term trends. Using archival RV data Keck/HIRES concert \textit{Gaia-Hipparcos} acceleration proper moti...

Context. A number of extrasolar planet systems contain pairs of Jupiter–like planets in mean motion resonances. As yet there are no known resonant systems which consist of a giant planet and a significantly lower–mass body. Aims. We investigate the evolution of two-planet systems embedded in a protoplanetary disc, which are composed of a Jupiter-mass planet plus another body located further out...