2017 OF201
 Orbit compared to Sedna | |
| Discovery | |
|---|---|
| Discovered by | Sihao Cheng, Jiaxuan Li, Eritas Yang |
| Discovery site | Cerro Tololo Inter-American Observatory |
| Designations | |
| 2017 OF201 | |
| TNO and eTNO | |
| Orbital characteristics | |
| Epoch (JD 2460800.5) | |
| Uncertainty parameter 3 | |
| Observation arc | 7.17 yr (2,618 days) |
| Earliest precovery date | 2011-08-31 |
| Aphelion | 1,700 AU |
| Perihelion | 45 AU |
| 880 AU | |
| Eccentricity | 0.95 |
| 25000±1000 yr | |
| 1.3° | |
| 0° 38m 7.8s / day | |
| Inclination | 16.21° |
| 329° | |
| 338° | |
| Physical characteristics | |
| ∼ 550 to 850 km (calc. for a typical TNO albedo of 0.15) | |
| 22.8 | |
| 3.5±0.5 | |
2017 OF201 is an extreme trans-Neptunian object and dwarf planet candidate, estimated to be at least 500 kilometres (300 miles) in diameter. With an absolute magnitude of between 3 and 4, it may be the brightest known object in the Solar system that does not have a directly estimated size. Its last perihelion was in November 1930.[1]
The discovery of 2017 OF201 may present a challenge to the hypothesis of the existence of Planet X/Planet 9. Most trans-neptunian objects with extremely wide and eccentric orbits tend to cluster. This clustering motivated the idea of a possible 9th planet influencing their orbit. Modeling of the hypothetical planet would have ejected 2017 OF201 from its current orbit over times scales less than 0.1 billion years. But since 2017 OF201 is currently in its orbit, this may present a challenge to the existence of Planet 9.[1][2]
Orbit
[edit]It orbits around the Sun at a distance of 880 astronomical units (AU) taking 2017 OF201 around 25,000 years to complete an orbit around the Sun. 2017 OF201 has an orbit with an eccentricity of 0.95 and an orbital inclination of 16.21°. 2017 OF201 has one of the most distant aphelia of known trans-Neptunian objects, being similar to 2013 SY99 and surpassed by 2019 EU5, all three of which have perihelia inside the Kuiper cliff and so have or have had some interaction with Neptune. This places this object near the estimated boundary of the Scattered disk region and some conceptions of an inner Oort cloud. The orbit of 2017 OF201 is shaped by both the planet Neptune and the galactic tide over timescales of over a billion years.[1][3]
Physical characteristics
[edit]The diameter of 2017 OF201 is unknown, but it is estimated to be somewhere between 550 and 850 kilometers in diameter, placing it within the range of other unlikely, but possible, dwarf planets. (See the list of possible dwarf planets.) For reference, Pluto is around 2,377 kilometers in diameter, and Quaoar, widely accepted as a dwarf planet, is 1,090 km.[1][2]
See also
[edit]References
[edit]- ^ a b c d Cheng, Sihao; Li, Jiaxuan; Yang, Eritas (2025-05-21), Discovery of a dwarf planet candidate in an extremely wide orbit: 2017 OF201, arXiv, doi:10.48550/arXiv.2505.15806, arXiv:2505.15806, retrieved 2025-05-23
- ^ a b "An Extreme Cousin for Pluto? Possible Dwarf Planet Discovered at Solar System's Edge - Press Release | Institute for Advanced Study". www.ias.edu. 2025-05-20. Retrieved 2025-05-23.
- ^ "An extreme cousin for Pluto? Possible dwarf planet discovered at solar system's edge". phys.org. Retrieved 2025-05-23.
- Discovery of a dwarf planet candidate in an extremely wide orbit: 2017 OF201 Sihao Cheng, Jiaxuan Li, Eritas Yang, 21 May 2025
External links
[edit]- 2017 OF201 at the JPL Small-Body Database
- Spin view of orbit, Sky trajectory 2011-2027 Tony Dunn
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| Consensus | _(cropped).jpg)  | ||||||||||||||
| Candidate (for TNOs, D+1σ ≥ 700 km or H ≤ 4.2) |
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