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

We report the discovery of a dwarf planet candidate, 2017 OF201, currently located at a distance of 90.5 au. Its orbit is extremely wide and extends to the inner Oort cloud, with a semi-major axis of 838 au and a perihelion of 44.9 au precisely determined from 19 observations over seven years. Assuming a typical albedo of 0.15, we estimate a diameter about 700 km, making it the second-largest known object in this dynamical population and a likely dwarf planet. Its high eccentricity suggests that it is part of a broader, unseen population of similar objects totaling about 1 % of Earth's mass. Notably, the orbit of 2017 OF201 lies well outside the clustering of longitude of perihelion observed in extreme trans-Neptunian objects, which has been proposed as dynamical evidence for a distant, undetected planet.