| Full text | |
| Author(s): |
de Sousa, Rafael Ribeiro
;
Izidoro, Andre
;
Morbidelli, Alessandro
;
Nesvorny, David
;
Winter, Othon Cabo
Total Authors: 5
|
| Document type: | Journal article |
| Source: | ICARUS; v. 433, p. 12-pg., 2025-06-01. |
| Abstract | |
A group of newly observed extreme trans-Neptunian objects show an unexpected level of orbital confinement, characterized by an approximate alignment of the orbital angular momentum vectors and apsidal lines. It has been proposed that a yet undiscovered giant planet (named Planet-9,) exists in the outer parts of the solar system and is causing this clustering. Initial studies suggested that Planet-9 could be as massive as 15M(circle plus). In this mass range, however, this planet tends to strongly interact with scattered disk objects (SDOS; 50 < a < 1000 au) and influence the dynamics and the orbits of a population of short period comets known as ecliptic comets. The outcome of this interaction is a population of ecliptic comets with orbital inclinations broadly inconsistent with observations. In this work, we model the formation and long-term dynamical evolution of trans-Neptunian object populations and Oort cloud during the solar system dynamical instability phase considering a revised set of mass and orbital parameters for Planet-9. In our simulation, Planet-9, is assumed to have a mass of m(9 )similar to 7.5M(circle plus), a moderately inclined orbit with i(9 )similar to 20 deg, semi-major axis a(9 )similar to 600 au, and orbital eccentricity of e(9 )similar to 0.3. Our results show that a relatively less massive Planet-9 is broadly consistent with the inclination distribution of trans-Neptunian objects and the observed number of ecliptic comets (D > 10 km) in the solar system. Furthermore, our results indicate that under the influence of Planet-9, distant Kuiper belt objects with 40 < q < 100au and 200 < a < 500au that are significantly inclined, are more likely to be apsidally aligned with the planet rather than anti-aligned, with an anti-aligned-to-aligned population ratio of approximately 0.5-0.7. Objects within this semi-major axis and perihelion range and with orbital inclinations lower than less than or similar to 20 deg (comparable to that assumed for Planet-9), however, exhibit significant apsidal anti-alignment. Within this low-inclination subset, the ratio of anti-aligned to aligned populations is approximately 2-4. These findings provide a novel observational direction that could help refine the search for this putative planet. (AU) | |
| FAPESP's process: | 16/24561-0 - On the relevance of small bodies in orbital dynamics |
| Grantee: | Othon Cabo Winter |
| Support Opportunities: | Research Projects - Thematic Grants |