Was there a Home-made Rogue Planet in the Early Solar System?
by
Tsung-Dao Lee Institute/S4F-SW - Open Area
Tsung-Dao Lee Institute
Host: Kangrou Guo/Dong Lai
Location: TDLI, Open Area (4F-SW)
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Abstract:
Over the past two decades, outer Solar System surveys have greatly expanded our inventory of Trans-Neptunian Objects (TNOs), revealing complex structures in the Kuiper Belt that challenge our understanding of the early Solar System. Notably, there is a substantial icy body population in the distant Kuiper Belt beyond 50 au, including a group of objects known as Sednoids. I propose that a super-Earth-mass planet, temporarily present in the early Solar System, dubbed a “rogue planet”, can account for these observed features. My simulations demonstrate that such a rogue planet can sufficiently populate the distant Kuiper Belt while preserving the low-inclination cold classical belt, consistent with recent observation surveys. One observable constraint to test the rogue planet hypothesis is the primordial orbital alignment of sednoids. By integrating the orbits of the four known sednoids backward over the age of the Solar System, I find that their apsidal lines tightly clustered only once, around 4.2 Gyr ago, indicating a primordial event imprinted a particular apsidal orientation on early TNOs. If future Solar System surveys (e.g., LSST and FOSSIL-SSR) confirm this finding, it would strongly support the rogue planet hypothesis as a coherent explanation for the formation of the outer Solar System.
Biography:
Yukun Huang is a postdoctoral fellow at the National Astronomical Observatory of Japan. He received his PhD in Astronomy from the University of British Columbia in 2023, after earning a Master’s degree in Aerospace Science from Tsinghua University in 2019. His research focuses on the formation and evolution of the Solar System, with particular interest in planetary dynamics and the Kuiper Belt. Much of his work involves modeling the orbital evolution of small bodies to uncover the Solar System’s early history. He is also a member of the CLASSY and FOSSIL outer Solar System surveys, dedicated to discovering and tracking distant, faint TNOs beyond Neptune.
