New Dwarf Planet Spotted Past Pluto

telcodad

An extreme cousin for Pluto? Possible dwarf planet discovered at solar system’s edge
by Lee Sandberg, Phys.org - May 22, 2025
https://phys.org/news/2025-05-extreme-cousin-pluto-dwarf-planet.html

A small team led by Sihao Cheng, Martin A. and Helen Chooljian Member in the Institute for Advanced Study’s School of Natural Sciences, has discovered an extraordinary trans-Neptunian object (TNO), named 2017 OF201, at the edge of our solar system.

The TNO is potentially large enough to qualify as a dwarf planet, the same category as the much more well-known Pluto. The new object is one of the most distant visible objects in our solar system and, significantly, suggests that the empty section of space thought to exist beyond Neptune in the Kuiper Belt is not, in fact, empty at all.

Cheng made the discovery alongside colleagues Jiaxuan Li and Eritas Yang from Princeton University, using advanced computational methods to identify the object’s distinctive trajectory pattern on the sky. The new object was officially announced by the International Astronomical Union’s Minor Planet Center on May 21, 2025 …

“The object’s aphelion—the farthest point on the orbit from the sun—is more than 1600 times that of Earth’s orbit,” explains Cheng. “Meanwhile, its perihelion—the closest point on its orbit to the sun—is 44.5 times that of Earth’s orbit, similar to Pluto’s orbit.” This extreme orbit, which takes the object approximately 25,000 years to complete, suggests a complex history of gravitational interactions. ….

px_eliezer_

telcodad This extreme orbit, which takes the object approximately 25,000 years to complete, suggests a complex history of gravitational interactions. ….

That’s interesting because, while Pluto’s rotation is believed to be 248 years, when Pluto was first discovered its rotation was ALSO described as taking about 25,000 years until better data was obtained.

I read that in an old astronomy book, MANY years ago….

WalterDnes

Pluto was discovered in the “BCE” (Before Computer Era) days. Articles about Pluto’s discovery refer to Clyde Tombaugh doing manual grunt work with a “blink comparator”. Nowadays, computers can go through older digital photos, looking for the object in question. The Wikipedia article https://en.wikipedia.org/wiki/2017_OF201 points out that its “observation arc” (period of observational data) is 7.17 yr (2,618 days), presumably from 2017 to 2024, at which point the article went out to peer review. I think the 25,000 ± 1000 year estimate is not wildly out. It’ll get narrowed down as we accumulate more observations.