 Hubble Space Telescope image of2001 UR163 taken in 2005 | |
| Discovery[1][2] | |
|---|---|
| Discovered by | DES |
| Discovery site | Kitt Peak National Obs. |
| Discovery date | 21 October 2001 |
| Designations | |
| (42301)2001 UR163 | |
| 2001 UR163 | |
| TNO[3] · 4:9 res[4][5] distant[1] | |
| Orbital characteristics[3] | |
| Epoch 1 July 2021 (JD 2459396.5) | |
| Uncertainty parameter 2[1][3] | |
| Observation arc | 38.45yr (14,045 d) |
| Aphelion | 66.643AU |
| Perihelion | 36.987 AU |
| 51.815 AU | |
| Eccentricity | 0.2862 |
| 372.98 yr (136,232 d) | |
| 80.814° | |
| 0° 0m 9.36s / day | |
| Inclination | 0.7531° |
| 301.39° | |
| 8 October 1937 | |
| 344.50° | |
| Physical characteristics | |
| 352±85 km[4][6]: 26 | |
| 0.209±0.08[4][6] | |
| 21.3[9] | |
| 4.21[1][3] | |
(42301) 2001 UR163 (provisional designation2001 UR163) is a resonanttrans-Neptunian object located in the outermost region of theSolar System. The object measures approximately 352 kilometers (220 miles) in diameter with a highalbedo and stays in an uncommonorbital resonance (4:9) with Neptune. It was discovered on 21 October 2001 by astronomers of theDeep Ecliptic Survey program atKitt Peak National Observatory near Tucson, Arizona, United States. As of 2021[update], it has not beennamed.[1]
The object orbits the Sun at a distance of 37.0–66.6 AU once every 372 years and 12 months (136,232 days;semi-major axis of 51.82 AU). Its orbit has aneccentricity of 0.29 and aninclination of 1° with respect to theecliptic.[3] It came toperihelion on 8 October 1937, and has since been moving away from the Sun.[3] In 2006, it moved beyond a distance of 50 AU and is at 53.7 AU as of 2021[update].[9] The body'sobservation arc begins with aprecovery, published by theDigitized Sky Survey and taken at theSiding Spring Observatory in July 1982.[1]
2001 UR163 wasnumbered (42301) by theMinor Planet Center on 26 May 2002 (M.P.C. 45686).[10] As of 2021[update], it has not beennamed.[1] According to the establishednaming conventions, it will receive a mythological or mythic name (not necessarily from Classical mythology), in particular one associated with creation.[11]
Lightcurve analysis shows only small deviations, suggesting that2001 UR163 is a spheroid with small albedo spots.[12] Observations withSpitzer'sInfrared Array Camera were used to study the body's surface composition. The analyzed data indicate the presence of 20%water ice, 60% amorphoussilicates, and 20% organic compounds, including complex ones such astholins.[6]: 20
2001 UR163 measures approximately 352 kilometers (220 miles) in diameter with a highalbedo of 0.209.[4][6]: 26
Based on previous estimates published on the Lightcurve Data Base and on Michael Brown's website,2001 UR163 measures between 531 km (330 mi) and 583 kilometers (360 miles), using an assumed intermediatesurface albedo of 0.09 to 0.10 with anabsolute magnitude of 4.49 and 4.4, respectively.[7][13]
