Discovery of a Dwarf Planet Candidate in an Extremely Wide Orbit: 2017 OF201
2025/05/21 by Sihao Cheng, Jiaxuan 嘉轩 Li 李, Jiaxuan Li +4 · 11 voices · 2 citations
Physics and Astronomy · #Astro and Planetary Science #Stellar, planetary, and galactic studies #Gamma-ray bursts and supernovae
paper · pdf · doi:10.3847/2041-8213/ae3a75
Abstract
Abstract We report the discovery of a dwarf planet candidate, 2017 OF201, currently located at a distance of 90 au. Its orbit is extremely wide and extends to the inner Oort cloud, with a semimajor axis of 830 au and a perihelion of 45 au, precisely determined from 24 observations over 20 yr. Assuming a typical albedo of 0.13, we estimate a diameter ∼700 km, making it the second-largest known object in this dynamical population and a dwarf planet candidate with the widest orbit. Its high eccentricity suggests that an unseen population of similar objects would total ∼1% of Earth’s mass. Notably, the longitude of perihelion of 2017 OF201 lies outside the clustering observed in extreme trans-Neptunian objects, posing a challenge to the proposed dynamical evidence for the hypothetical Planet Nine.
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Discussions
- 🚨 New dwarf planet candidate: 2017 OF201 🚨 ~700 km wide, now 90.5 AU from the Sun. Orbit: a = 838 AU, q = 44.9 AU — deep into the inner Oort Cloud. Possibly part of a hidden population totaling ~1% [bsky, 56 points, 4 comments]
- Nice surprise at the arxiv today: Cheng et al. report the discovery of a new dwarf planet (candidate, 700 km dia) in the scattered disk (a=838 au, q=44.9 au). Not adding to clustering. N-body simulati [bsky, 23 points, 1 comments]
- Discovery of new extreme trans-Neptunian (TNO) object 2017 OF201. Large enough at 700 km diameter to qualify as a dwarf planet. Orbit with aphelion of 1,632 AU extends to the inner Oort cloud and cove [bsky, 21 points, 0 comments]
- Cool paper on arXiv: arxiv.org/abs/2505.15806 I for a minute thought this was DES data and I missed it, but it’s not [bsky, 9 points, 0 comments]
- We’re reading “Discovery of a dwarf planet candidate in an extremely wide orbit: 2017 OF201” Key quote: “The orbit of 2017 OF201 also presents an intriguing challenge to the Planet X / Planet 9 hypoth [bsky, 3 points, 1 comments]
- 2017 OF201 発見の論文こちら。 90.5天文単位の距離で発見され、直径700kmと測定された。 それって太陽から？地球から？と思いましたが…どちらからでも大差ないな。 arxiv.org/abs/2505.15806 [bsky, 2 points, 1 comments]
- @plutokiller.com Good morning Dr, it seems we have a problem arxiv.org/abs/2505.15806 [bsky, 1 points, 1 comments]
- Are you discussing the issue because of this dwarf planet? arxiv.org/abs/2505.15806 [bsky, 1 points, 2 comments]
- What say you @astrokiwi.bsky.social? "Discovery of a dwarf planet candidate in an extremely wide orbit: 2017 OF201" arxiv.org/pdf/2505.15806 [bsky, 1 points, 0 comments]
- Feed: "AAS Nova"
By: Kerry Hensley on Thursday, April 23, 2026 [bsky, 0 points, 0 comments]
- arxiv.org/abs/2505.158... [bsky, 0 points, 0 comments]
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