The formation of giant planets in wide orbits by photoevaporation-synchronized migration

MILLER BERTOLAMI, M. M.; MILLER BERTOLAMI, M. M.; GUILERA, O. M.; GUILERA, O. M.; RONCO, M. P.; RONCO, M. P.

Monthly Notices of the Royal Astronomical Society: Letters

Monthly Notices of the Royal Astronomical Society: Letters

Año: 2017 vol. 471 p. 16 - 20

1745-3925

The discovery ofgiant planets in wide orbits represents a major challenge for planetformation theory. In the standard core accretion paradigm planets areexpected to form at radial distances <~ 20 au in order to formmassive cores (with masses <~ 10Mearth) able to trigger thegaseous runaway growth before the dissipation of the disc. Thishasencouraged authors to nd modications of the standardscenario as well as alternative theories like the formation ofplanets by gravitational instabilities in the disc to explain theexistence of giant planets in wide orbits. However, there is not yetconsensus on how these systems are formed. In this letter, we presenta new natural mechanism for the formation of giant planets in wideorbits within the core accretion paradigm. If photoevaporation isconsidered, after a few Myr of viscous evolution a gap in the gaseousdisc is opened. We found that, under particular circumstances planetmigration becomes synchronizedwith the evolution of the gap,which results in an ecient outward planet migration. This mechanismis found to allow the formation of giant planets with masses Mp ~MJup in wide stable orbits as large as 130 au from the central star.p { margin-bottom: 0.25cm; line-height: 120%; }