78799 Xewioso (provisional designation 2002 XW93) is a trans-Neptunian object located in the inner edge of the Kuiper belt. It has a dark surface with a diameter between 490 and 640 kilometers (300 and 400 mi). It was discovered on 10 December 2002 by astronomers at Palomar Observatory in California.[1]
 Hubble Space Telescope image of Xewioso taken on 20 September 2008 | |
| Discovery[1][2] | |
|---|---|
| Discovered by | Palomar Obs. |
| Discovery site | Palomar Obs. |
| Discovery date | 10 December 2002 |
| Designations | |
| Pronunciation | /ˌhɛviˈoʊsoʊ/ |
Named after | Xɛvioso |
| 2002 XW93 | |
| TNO[2] · classical (inner/hot)[3]: 2 · other TNO[4] · distant[1] | |
| Orbital characteristics[2] | |
| Epoch 2025 May 05 (JD 2460800.5) | |
| Uncertainty parameter 2 | |
| Observation arc | 35.19 yr (12,854 d) |
| Earliest precovery date | 17 December 1989 |
| Aphelion | 46.88 AU |
| Perihelion | 28.49 AU |
| 37.68 AU | |
| Eccentricity | 0.2439 |
| 231.33 yr (84493±4 d) | |
| 153.53° | |
| 0° 0m 15.34s / day | |
| Inclination | 14.3307° |
| 46.700° | |
| 248.55° | |
| Known satellites | 0 |
| Physical characteristics | |
| 565+71 −73 km[3]: 10 | |
| 0.038+0.043 −0.025[3]: 10 | |
| 5.4±0.7[3]: 7 4.86 (JPL/MPC)[1][2] | |
History
editDiscovery
edit
Xewioso was discovered on 10 December 2002 by a team of astronomers at Palomar Observatory in California.[1] The discovery team included Chad Trujillo, Michael E. Brown, Eleanor F. Helin, Steven Pravdo, Kenneth Lawrence, Michael D. Hicks, who were using Palomar's 1.22-meter (48 in) Samuel Oschin telescope.[5] Follow-up observations were taken by Trujillo using Palomar's 1.52-meter (60 in) telescope on 4 and 5 January 2003, and results were reported to the Minor Planet Center.[5][6]: 101 The team's discovery of Xewioso alongside the trans-Neptunian objects 2002 WC19 and 2002 XV93 was announced by the MPC on 5 January 2003.[5] The discovery of Xewioso formed part of Trujillo and Brown's Caltech Wide Area Sky Survey at Palomar Observatory, which aimed to find bright, Pluto-sized Kuiper belt objects like Quaoar, Máni, and Aya.[6]: 103
In December 2003, the MPC published the first identified precovery observations of Xewioso, which included a pair of photographic plates from Palomar Observatory's Digitized Sky Survey.[7] The earliest of these photographic plates came from 17 December 1989, which was found by Reiner M. Stoss.[7] This 1989 plate remains as the earliest known precovery observation of Xewioso.[1]
Naming and numbering
editThe object is named after Xɛ̀vioso, a thunder god in the mythologies of the Tado (Fon and Ewe) peoples of West Africa.[8]: 6 The naming of this object was announced by the International Astronomical Union's Working Group for Small Body Nomenclature on 1 September 2025.[8] Before Xewioso was officially named, it was known by its provisional designation 2002 XW93,[1] which indicates the year and half-month of the object's discovery date.[9] Xewioso's minor planet catalog number of 78799 was given by the MPC on 6 February 2004.[10]
Orbit and classification
edit
Xewioso orbits the Sun at a distance of 28–47 AU (average 38 AU) once about every 230 years.[2] Since its average orbital distance or semi-major axis is greater than Neptune's, Xewioso is considered a trans-Neptunian object.[2] Its orbit has an eccentricity of 0.24 and an inclination of 14° with respect to the ecliptic.[2] It previously passed perihelion in 1926, when it was nearest to the Sun.[2]
Xewioso orbits at the inner edge of the Kuiper belt with a high orbital inclination, so it can be considered an inner classical Kuiper belt object of the dynamically "hot" (high-inclination) population.[3]: 2 Because Xewioso's orbit crosses Neptune's orbit, it can also be technically considered a centaur according to the Deep Ecliptic Survey's definition.[3]: 2
Physical characteristics
editXewioso is a dark object with an extremely low geometric albedo of between 0.01 and 0.08 and an absolute magnitude of 5.4, which corresponds to a diameter of roughly 490 to 640 km (300 to 400 mi).[3]: 10, 12 These measurements come from 2010 observations by the Herschel Space Observatory, which could determine Xewioso's size by detecting its far-infrared thermal emission.[3]: 4 However the color and rotation period of Xewioso are unknown and its absolute magnitude also has significant uncertainty.[3]: 3
Based on its size of 565+71
−73 km,[3]: 10 it belongs to the proposed class of "mid-sized" TNOs between 400 and 1,000 km (250 and 620 mi) in diameter, which are believed to represent the transition between small, low-density TNOs and large, high-density dwarf planets.[11][12]: 1 Planetary scientists have hypothesized that mid-sized TNOs should have highly porous and unheated interiors, because TNOs in this size range (namely Uni and Gǃkúnǁʼhòmdímà) have been found to have low densities around 1 g/cm3.[11] However, Xewioso is not known to have any natural satellites or moons, which means there is currently no way to measure its mass and density.[13]: 1, 3
See also
editReferences
edit- 1 2 3 4 5 6 7 "(78799) Xewioso = 2002 XW93". Minor Planet Center. Retrieved 17 November 2018.
- 1 2 3 4 5 6 7 8 "JPL Small-Body Database Lookup: 78799 Xewioso (2002 XW93)" (2025-02-25 last obs.). Jet Propulsion Laboratory. Retrieved 19 August 2025.
- 1 2 3 4 5 6 7 8 9 10 Vilenius, E.; Kiss, C.; Mommert, M.; Müller, T.; Santos-Sanz, P.; Pal, A.; et al. (May 2012). ""TNOs are Cool": A survey of the trans-Neptunian region VI. Herschel/PACS observations and thermal modeling of 19 classical Kuiper belt objects" (PDF). Astronomy & Astrophysics. 541: 17. arXiv:1204.0697. Bibcode:2012A&A...541A..94V. doi:10.1051/0004-6361/201118743. S2CID 54222700. A94.
- ↑ Johnston, Wm. Robert (7 October 2018). "List of Known Trans-Neptunian Objects". Johnston's Archive. Retrieved 14 November 2018.
- 1 2 3 Trujillo, C. A.; Brown, M. E.; Helin, E. F.; Pravdo, S.; Lawrence, K.; Hicks, M. (5 January 2003). Marsden, Brian G. (ed.). "MPEC 2003-A25 : 2002 WC19, 2002 XV93, 2002 XW93". Minor Planet Electronic Circular. 2003-A25. Minor Planet Center. Retrieved 30 October 2025.
- 1 2 Trujillo, C. A.; Brown, M. E. (June 2003). "The Caltech Wide Area Sky Survey". Earth, Moon, and Planets. 92 (1): 99–112. Bibcode:2003EM&P...92...99T. doi:10.1023/B:MOON.0000031929.19729.a1. S2CID 189905639.
- 1 2 Stoss, R.; Meyer, E.; Wasserman, L. H.; Chiang, E. I.; Lovering, J. R.; Clancy, K. B. (24 December 2003). Marsden, Brian G. (ed.). "MPEC 2003-Y55 : 2002 XW93". Minor Planet Electronic Circular. 2003-Y55. Minor Planet Center. Bibcode:2003MPEC....Y...55S. Retrieved 30 October 2025.
- 1 2 "WGSBN Bulletin 5, #20" (PDF). WGSBN Bulletin. 5 (20). International Astronomical Union. 1 September 2025. Retrieved 1 September 2025.
- ↑ "New- And Old-Style Minor Planet Designations". Minor Planet Center. Retrieved 30 October 2025.
- ↑ "M.P.C. 50967" (PDF). Minor Planet Circulars (50967). Minor Planet Center: 413. 6 February 2004. Retrieved 30 October 2025.
- 1 2 Grundy, W. M.; Noll, K. S.; Buie, M. W.; Benecchi, S. D.; Ragozzine, D.; Roe, H. G. (December 2019). "The Mutual Orbit, Mass, and Density of Transneptunian Binary Gǃkúnǁʼhòmdímà ((229762) 2007 UK126)" (PDF). Icarus. 334: 30–38. Bibcode:2019Icar..334...30G. doi:10.1016/j.icarus.2018.12.037. S2CID 126574999.
- ↑ Sheppard, Scott; Fernandez, Yanga; Moullet, Arielle (6 September 2018). "The Albedos, Sizes, Colors and Satellites of Dwarf Planets Compared with Newly Measured Dwarf Planet 2013 FY27". The Astronomical Journal. 156 (6): 270. arXiv:1809.02184. Bibcode:2018AJ....156..270S. doi:10.3847/1538-3881/aae92a. S2CID 119522310.
- ↑ Grundy, W. M.; McKinnon, W. B.; Ammannito, E.; Aung, M.; Bellerose, J.; Brenker, F.; et al. (December 2009). Exploration Strategy for the Ice Dwarf Planets 2013-2022 (PDF). American Geophysical Union Fall Meeting 2009. Bibcode:2009AGUFM.P43D1471G. P43D-1471. Archived from the original (PDF) on 30 March 2025.
External links
edit
- 78799 Xewioso at AstDyS-2, Asteroids—Dynamic Site
- 78799 Xewioso at the JPL Small-Body Database
