AR 13898 (Archival Research)

Sun Jul 14 04:34:42 GMT 2024

Principal Investigator: Nathan Kaib
PI Institution: University of Oklahoma Norman Campus
Investigators (xml)

Title: The Influence of Stellar Companions on Fomalhaut's Planetary System
Cycle: 22

The Fomalhaut star system has been targeted by at least 11 HST observing programs, resulting in nearly 150 orbits of observations that have uncovered an eccentric dust ring and a directly imaged exoplanet candidate on an extreme orbit. Despite extensive observational and theoretical study, a self-consistent explanation for this system's structure has yet to be found. However, the Fomalhuat system also contains two distant stellar companions orbiting at 57000 AU and 158000 AU whose dynamics are largely unexplored. We have recently shown that the influence of such distant stellar companions on the structure and evolution of planetary systems can often be {counterintuitively} quite dramatic. Based on preliminary work, we believe Fomalhaut's stellar companions {in particular the closer star} may account for the dust ring's eccentricity and possibly the imaged planet's orbit. We propose to use numerical simulations to thoroughly characterize the orbital evolution of Fomalhaut's stellar companions and assess the probability that they can produce the observed ring's eccentricity. These simulations will also provide mass constraints on the total ring material as well as mass and orbital architecture constraints on any undetected planets orbiting interior to Fomalhaut's ring. Understanding the potential role of Fomalhaut's stellar companions will offer new insights into HST's perplexing observations of this system.