Formation of a wide-orbit giant planet in a gravitationally unstable subsolar-metallicity protoplanetary disc
- Author(s)
- Ryoki Matsukoba, Eduard I. Vorobyov, Takashi Hosokawa, Manuel Guedel
- Abstract
Direct imaging observations of planets revealed that wide-orbit (>10 au) giant planets exist even around subsolar-metallicity host stars and do not require metal-rich environments for their formation. A possible formation mechanism of wide-orbit giant planets in subsolar-metallicity environments is the gravitational fragmentation of massive protoplanetary discs. Here, we follow the long-term evolution of the disc for 1 Myr after its formation, which is comparable to disc lifetime, by way of a two-dimensional thin-disc hydrodynamic simulation with the metallicity of 0.1. We find a giant protoplanet that survives until the end of the simulation. The protoplanet is formed by the merger of two gaseous clumps at ∼0.5 Myr after disc formation, and then it orbits ∼200 au from the host star for ∼0.5 Myr. The protoplanet's mass is ∼10 MJ at birth and gradually decreases to 1 MJ due to the tidal effect from the host star. The result provides the minimum mass of 1 MJ for the protoplanet in our simulation. We anticipate that the mass of a protoplanet experiencing reduced mass loss thanks to the protoplanetary contraction in higher resolution simulations can increase to ∼10 MJ. We argue that the disc gravitational fragmentation would be a promising pathway to form wide-orbit giant planets with masses of ≥1 MJ in subsolar-metallicity environments.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Southern Federal University, Kyoto University
- Journal
- Monthly Notices of the Royal Astronomical Society
- Volume
- 526
- Pages
- 3933-3943
- No. of pages
- 11
- ISSN
- 0035-8711
- DOI
- https://doi.org/10.1093/mnras/stad3003
- Publication date
- 12-2023
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics, 103038 Space exploration
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/formation-of-a-wideorbit-giant-planet-in-a-gravitationally-unstable-subsolarmetallicity-protoplanetary-disc(34391396-6f46-4328-a553-88a45a755fbc).html