Slowly-growing gap-opening planets trigger weaker vortices

Michael Hammer, Kaitlin M. Kratter, Min Kai Lin

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

The presence of a giant planet in a low-viscosity disc can create a gap edge in the disc's radial density profile sharp enough to excite the Rossby wave instability. This instability may evolve into dust-trapping vortices that might explain the 'banana-shaped' features in recently observed asymmetric transition discs with inner cavities. Previous hydrodynamical simulations of planet-induced vortices have neglected the time-scale of hundreds to thousands of orbits to grow a massive planet to Jupiter size. In this work, we study the effect of a giant planet's runaway growth time-scale on the lifetime and characteristics of the resulting vortex. For two different planet masses (1 and 5 Jupiter masses) and two different disc viscosities (α = 3 × 10-4 and 3 × 10-5), we compare the vortices induced by planets with several different growth time-scales between 10 and 4000 planet orbits. In general, we find that slowly-growing planets create significantly weaker vortices with lifetimes and surface densities reduced by more than 50 per cent. For the higher disc viscosity, the longest growth time-scales in our study inhibit vortex formation altogether. Additionally, slowly-growing planets produce vortices that are up to twice as elongated, with azimuthal extents well above 180° in some cases. These unique, elongated vortices likely create a distinct signature in the dust observations that differentiates them from the more concentrated vortices that correspond to planets with faster growth time-scales. Lastly, we find that the low viscosities necessary for vortex formation likely prevent planets from growing quickly enough to trigger the instability in self-consistent models.

Original languageEnglish (US)
Pages (from-to)3533-3543
Number of pages11
JournalMonthly Notices of the Royal Astronomical Society
Volume466
Issue number3
DOIs
StatePublished - Jan 1 2017

Keywords

  • Disc interactions
  • Hydrodynamics
  • Instabilities
  • Methods: numerical
  • Planet
  • Protoplanetary discs

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'Slowly-growing gap-opening planets trigger weaker vortices'. Together they form a unique fingerprint.

  • Cite this