Insights on the dynamical history of the Fomalhaut system - Investigating the Fom c hypothesis
arXiv:1409.6868 · doi:10.1051/0004-6361/201424691
Abstract
The eccentric shape of the debris disk observed around Fomalhaut was first attributed to Fom b, a companion detected near the belt inner-edge, but new constraints on its orbit revealed that it is belt-crossing, highly eccentric , and can hardly account for the shape of the belt. The best scenario to explain this paradox is that there is another massive body in this system, Fom c, which drives the debris disk shape. The resulting planetary system is highly unstable, which hints at a dynamical scenario involving a recent scattering of Fom b on its current orbit, potentially with the putative Fom c. Our goal is to give insights on the probability for Fom b to have been set on its highly eccentric orbit by a close-encounter with the putative Fom c. We aim to study in particular the part played by mean-motion resonances with Fom c, which could have brought Fom b sufficiently close to Fom c for it to be scattered on its current orbit, but also delay this scattering event. Using N-body simulations, we found that the generation of orbits similar to that of Fom b, either in term of dimensions or orientation, is a robust process involving a scattering event and a further secular evolution of inner material with an eccentric massive body such as the putative Fom c. We found in particular that mean-motion resonances can delay scattering events, and thus the production of Fom b-like orbits, on timescales comparable to the age of the system, thus explaining the witnessing of an unstable configuration. We conclude that Fom b probably originated from an inner resonance with Fom c, which is at least Neptune-Saturn size, and was set on its current orbit by a scattering event with Fom c. Since Fom b could not have formed from material in resonance, our scenario also hints at former migration processes in this planetary system.
References in corpus (26)
- Optical Images of an Exosolar Planet 25 Light Years from Earth
- A planetary system as the origin of structure in Fomalhaut's dust belt
- How Observations of Circumstellar Disk Asymmetries Can Reveal Hidden Planets: Pericenter Glow and its Application to the HR 4796 Disk
- Fomalhaut's Debris Disk and Planet: Constraining the Mass of Fomalhaut b From Disk Morphology
- On the Age and Binarity of Fomalhaut
- Predictions for a planet just inside Fomalhaut's eccentric ring
- A near-infrared interferometric survey of debris disc stars. III. First statistics based on 42 stars observed with CHARA/FLUOR
- Long range outward migration of giant planets, with application to Fomalhaut b
- The Solar Neighborhood XXX: Fomalhaut C
- Scattering of small bodies by planets: a potential origin for exozodiacal dust ?
- Infrared Non-detection of Fomalhaut b -- Implications for the Planet Interpretation
- Influence of an inner disc on the orbital evolution of massive planets migrating in resonance
- Dependence of a planet's chaotic zone on particle eccentricity: the shape of debris disc inner edges
- Planetesimal driven migration as an explanation for observations of high levels of warm, exozodiacal dust
- Fomalhaut b: Independent Analysis of the Hubble Space Telescope Public Archive Data
- Collisional Evolution of Irregular Satellite Swarms: Detectable Dust around Solar System and Extrasolar Planets
- Numerical Modelling of Dusty Debris Disks
- An interferometric study of the Fomalhaut inner debris disk. III. Detailed models of the exozodiacal disk and its origin
- An independent determination of Fomalhaut b's orbit and the dynamical effects on the outer dust belt
- Predictions for Shepherding Planets in Scattered Light Images of Debris Disks
- Spitzer/IRAC Limits to Planetary Companions of Fomalhaut and epsilon Eridani
- Consequences of an Eccentric Orbit for Fomalhaut b
- Can eccentric debris disks be long-lived? A first numerical investigation and application to Reticuli
- Fomalhaut b as a Cloud of Dust: Testing Aspects of Planet Formation Theory
- Dancing with the Stars: Formation of the Fomalhaut triple system and its effect on the debris disks
- A Deep Keck/NIRC2 Search for Thermal Emission from Planetary Companions Orbiting Fomalhaut
Cited by in corpus (15)
- Exocometary gas in the HD 181327 debris ring
- A gap in the planetesimal disc around HD 107146 and asymmetric warm dust emission revealed by ALMA
- Planet populations inferred from debris discs: insights from 178 debris systems in the ISPY, LEECH and LIStEN planet-hunting surveys
- Inner mean-motion resonances with eccentric planets: A possible origin for exozodiacal dust clouds
- Insights into the planetary dynamics of HD 206893 with ALMA
- From scattered-light to millimeter emission: A comprehensive view of the Gyr-old system of HD 202628 and its eccentric debris ring
- Constraining the orbits of sub-stellar companions imaged over short orbital arcs
- Constraints on the architecture of the HD 95086 planetary system with the Gemini Planet Imager
- Fomalhaut b could be massive and sculpting the narrow, eccentric debris disc, if in mean-motion resonance with it
- Biases in orbit fitting of directly-imaged exoplanets with small orbital coverage
- Models of the Eta Corvi debris disk from the Keck Interferometer, Spitzer and Herschel
- ALMA imaging of the M-dwarf Fomalhaut C's debris disc
- Constraints on the gas content of the Fomalhaut debris belt. Can gas-dust interactions explain the belt's morphology?
- 94 Ceti: a triple star with a planet and dust disc
- Interferometric Detection and Orbit Modeling of the Subcomponent in the Hot-dust System Tuc A: A Low-mass Star on an Eccentric Orbit in a Hierarchical-quintuple System