Scientists have found evidence of a previously-undetected dwarf planet at the edge of the solar system. The object, dubbed 2017 OF201, follows an extreme, oblong orbit, taking some 25,000 Earth ...

2017 OF201 is about one-third the size of Pluto, which was reclassified as a dwarf planet in August 2006, and "is likely large enough to qualify as a dwarf planet, and its orbit is extremely wide ...

Planet 9 May Be in Trouble The orbit of 2017 OF201 doesn’t just add a new name to the solar system; it throws a wrench into the Planet 9 hypothesis—a theory proposing a large, unseen planet ...

If there were one, that Planet Nine would "nudge the closest part of 2017 OF201's trajectory inward until Neptune flung it out of the solar system." Because 2017 OF201 is there, that could be an ...

Scientists are intrigued after spotting a highly unusual celestial object lurking at the very edge of our solar system. It's possible the trans-Neptunian object, dubbed 2017 OF201, is large enough ...

Cheng and his colleagues estimate 2017 OF 201 's diameter to be 700 km, which would make it the second largest known object in such a wide orbit. The diameter of Pluto, meanwhile, is 2,377 km.

More information: Sihao Cheng et al, Discovery of a dwarf planet candidate in an extremely wide orbit: 2017 OF201, arXiv (2025). DOI: 10.48550/arxiv.2505.15806 ...

2017 OF201 is a roughly spherical object and is estimated to be about 435 miles (700 kilometers) in diameter, making it the second largest body of its kind in the solar system with such a wide orbit.