WASHINGTON: Astronomers have stumbled upon a peculiar new object lurking far beyond Neptune, in one of the coldest and most remote areas of our solar system.
This icy newcomer, designated 2017 OF201, may be hefty enough to earn the title of dwarf planet and takes roughly 25,000 years to orbit the sun once.
Researchers believe it is among the farthest celestial entities we’ve ever spotted, suggesting that there may be even more hidden worlds waiting to be discovered.
They describe it as one of the most distant visible objects in our solar system, indicating that an extensive region beyond Neptune, known as the Kuiper Belt, might not be as empty as previously thought. The Kuiper Belt is filled with a variety of icy bodies.
The object belongs to a group known as trans-Neptunian objects, which orbit the sun at distances greater than Neptune.
2017 OF201 was identified through a series of observations made over seven years using telescopes in Chile and Hawaii.
“It is potentially large enough to be considered a dwarf planet. Its orbit is very wide and eccentric, suggesting it has undergone an intriguing orbital migration,” explained astrophysicist Sihao Cheng from the Institute for Advanced Study at Princeton, who led the research alongside graduate students Jiaxuan Li and Eritas Yang.
Its size is estimated to be slightly smaller than Ceres, the smallest recognized dwarf planet in our solar system, which has a diameter of around 590 miles (950 km). In contrast, Pluto, the largest of the dwarf planets, measures about 1,477 miles (2,377 km) in diameter.
2017 OF201’s mass estimates place it approximately 20,000 times lighter than Earth and 50 times lighter than Pluto.
“We don’t have a clear picture of its shape yet. Sadly, it’s too far away, making it challenging to resolve the details with telescopes,” Cheng mentioned. “We also don’t know its composition, but it’s likely to be similar to other icy objects.”
The discovery was confirmed by the Minor Planet Center of the International Astronomical Union, a global astronomer organization, and detailed in a study that is currently available on the open-access site arXiv, although it has not yet undergone peer review.
Earth’s distance from the sun is measured in astronomical units (AU). At present, 2017 OF201 is located 90.5 AU from the sun, which is 90.5 times farther than Earth.
During its most distant point in its orbit, 2017 OF201 travels over 1,600 AU from the sun, while at its closest, it is around 45 AU away. This means that at times, it can be nearer to the sun than Pluto, whose orbital distance varies from 30 to 49 AU as it follows an elliptical path around the sun.
The researchers speculate that 2017 OF201’s extreme orbit might be a result of gravitational interactions with a large planet in the past.
“We still lack understanding of the solar system’s distant reaches because direct observations are challenging beyond approximately 150 AU,” Cheng stated. “The presence of this single object implies there could be another hundred or so similar objects that are just too far to detect at this time.”
The five dwarf planets recognized by the International Astronomical Union, in order of their distance from the sun, are Ceres, Pluto, Haumea, Makemake, and Eris, all orbiting beyond Neptune.
The organization distinguishes between planets and dwarf planets. A planet must orbit its host star (in our case, the sun) and be sufficiently large that its gravity clears its orbit of other objects of similar size. Conversely, a dwarf planet must also orbit the sun and be roughly spherical but has not cleared its orbital neighborhood of other similar-sized objects.
Cheng noted that the discovery of 2017 OF201 may have implications for theories surrounding the possible existence of a ninth planet, sometimes referred to as Planet X or Planet Nine.
This is due to the fact that 2017 OF201’s orbit does not fit the clustering pattern typically seen among known trans-Neptunian objects, which often group together. Some scientists theorized that such clustering could be influenced by a yet-to-be-found planet’s gravity.
“The existence of 2017 OF201 as an outlier could challenge this hypothesis,” Cheng concluded.
