Discovery of a dwarf planet candidate in an extremely wide orbit: 2017 OF201

TL;DR

The paper reports the discovery of a new dwarf planet candidate, 2017 OF201, with an extremely wide orbit extending to the inner Oort cloud, challenging existing theories about the influence of Planet Nine.

Contribution

It presents the discovery and orbital characterization of 2017 OF201, a dwarf planet candidate with the widest known orbit, and discusses its implications for Solar System dynamics.

Findings

2017 OF201 has a semi-major axis of 830 au.

Its diameter is approximately 700 km.

Its orbit challenges the clustering hypothesis related to Planet Nine.

Abstract

We report the discovery of a dwarf planet candidate, 2017 OF201, currently located at a distance of 90 au. Its orbit is extremely wide and extends to the inner Oort cloud, with a semi-major axis of 830 au and a perihelion of 45 au, precisely determined from 24 observations over 20 years. Assuming a typical albedo of 0.13, we estimate a diameter about 700 km, making it the second-largest known object in this dynamical population and a dwarf planet candidate with the widest orbit. Its high eccentricity suggests that an unseen population of similar objects would total about 1% of Earth's mass. Notably, the longitude of perihelion of 2017 OF201 lies outside the clustering observed in extreme trans-Neptunian objects, posing a challenge to the proposed dynamical evidence for the hypothetical Planet Nine.