A composite image showing the five dwarf planets recognized by the International Astronomical Union, plus the newly discovered trans-Neptunian object 2017 OF201.
Images of dwarf planets: NASA/JPL-Caltech; image of 2017 OF201: Sihao Cheng et al.
Princeton University graduate students Jiaxuan Li and Eritas Yang, together with Sihao Cheng from the Institute for Advanced Study, have discovered an exceptional trans-Neptunian object (TNO) that challenges our understanding of our solar system's outer reaches.
The newly discovered object, named 2017 OF201, is potentially large enough to qualify as a dwarf planet like Pluto. With an estimated diameter of 700 km, it's one of the most distant visible objects in our solar system. The extreme orbit of 2017 OF201 suggests that the previously presumed "empty" region beyond Neptune's Kuiper Belt may, in fact, contain numerous undiscovered bodies with similar orbital architectures.
"This object is in an extremely wide orbit that takes approximately 25,000 years to complete," explains Yang. "Its farthest point from the Sun is more than 1600 times that of Earth's orbit, while its closest approach is similar to Pluto's orbit." Li adds, "2017 OF201's unusual orbital geometry makes it particularly interesting, as it doesn't follow the clustering pattern observed in many extreme TNOs—potentially challenging current hypotheses about an unseen massive planet in our solar system."
Image showing the current location of Pluto, Neptune, and 2017 OF201
Figure credit: Jiaxuan Li (Princeton), Sihao Cheng (IAS)
Animation showing the movement of 2017 OF201 on the sky
Figure credit: Jiaxuan Li (Princeton), Sihao Cheng (IAS)
The team used advanced computational methods to identify the object's distinctive trajectory across astronomical images from the Victor M. Blanco Telescope and Canada-France-Hawaii Telescope collected over seven years. Upcoming wide-field sky surveys, including the Vera C. Rubin Observatory's Legacy Survey of Space and Time, will likely unveil many more objects similar to 2017 OF201.
The discovery highlights the value of open science, as Li notes: “All the data we used are publicly available archival resources, demonstrating that groundbreaking discoveries aren't limited to those with access to the world's largest telescopes.”
More information about this discovery can be found in the team's paper, now available on arXiv. This work is also highlighted by the Institute for Advanced Study.
Congratulations to Jiaxuan and Eritas on this remarkable discovery!