The formation of giant planets in wide orbits by photoevaporation-synchronised migration (Octavio Guilera; Instituto de Astrofísica de La Plata - UNLP-CONICET)

Desde Noviembre 15, 2017 13:15 hasta Noviembre 15, 2017 13:45

En Instituto de Astrofísica, Pontificia Universidad Católica, Vicuña Mackenna 4860, Santiago, Chile

Categorías: Seminarios

The discovery of giant planets in wide orbits represents a major challenge for planet formation theory. In the standard core accretion paradigm planets are expected to form at radial distances less than 20 au in order to form massive cores (with masses ~10 Earth masses) able to trigger the gaseous runaway growth before the dissipation of the disc. This has encouraged authors to find modifications of the standard scenario as well as alternative theories like the formation of planets by gravitational instabilities in the disc to explain the existence of giant planets in wide orbits. However, there is not yet consensus on how these systems are formed.

In this talk, we present a new natural mechanism for the formation of giant planets in wide orbits within the core accretion paradigm. If photoevaporation is considered, after a few Myr of viscous evolution a gap in the gaseous disc is opened. We found that, under particular circumstances planet migration becomes synchronised with the evolution of the gap, which results in an efficient outward planet migration. This mechanism is found to allow the formation of giant planets in wide stable orbits as large as ~100 au from the central star.