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Discovery[1]
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| Discovered by | Spacewatch (291) |
| Discovery date | October 30, 2002 |
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Designations
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| MPC designation | (55637) 2002 UX25 |
| Alternate name(s) | none |
| Minor planet category |
Cubewano (MPC)[2] Extended (DES)[3] |
| Epoch July 23, 2010 (JD 2455400.5 ) | |
| Aphelion | 7 318.7 Gm (48.923 AU) |
| Perihelion | 5 507.4 Gm (36.815 AU) |
| Semi-major axis | 6 413.1 Gm (42.869 AU) |
| Eccentricity | 0.14121 |
| Orbital period | 102522 d (280.69 yr) |
| Average orbital speed | 4.54 km/s |
| Mean anomaly | 289.85° |
| Inclination | 19.398° |
| Longitude of ascending node | 204.60° |
| Argument of perihelion | 275.49° |
| Satellites | One roughly 205 ± 55 km in diameter[5][6] |
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Physical characteristics
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| Dimensions | 681 +116 −114 km[7] |
| Mass | ≈3.3×1020? kg[8] |
| Mean density | 2.0? g/cm3 |
| Equatorial surface gravity | 0.2543? m/s2 |
| Escape velocity | 0.4811? km/s |
| Sidereal rotation period |
14.382 h[4] |
| Albedo | 0.115 +0.05 −0.03[7] |
| Temperature | ~43 K |
| Spectral type | (pushing red) B-V=1.12, V-R=0.61[9] B-V=0.95, V-R=0.56[10][11] |
| Apparent magnitude | 19.8[12] |
| Absolute magnitude (H) | 3.6[4] |
(55637) 2002 UX25 is a Spitzer dwarf-planet candidate that orbits the Sun in the Kuiper belt beyond Neptune. It takes roughly 280 years to orbit the Sun, and it has one known moon.
It is a trans-Neptunian object with an absolute magnitude of 3.6,[4] making it a dwarf planet candidate. The Spitzer Space Telescope estimates it to be about 681 km in diameter.[7] It was discovered on October 30, 2002, by the Spacewatch program.[1] It is a mid-sized cubewano similar to (20000) Varuna.
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Contents
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A variability of the visual brightness was detected which could be fit to a period of 14.38 or 16.78 h (depending on a single-peaked or double peaked curve).[13]
The Spitzer Space Telescope has estimated it to have a size of 681 +116
−114 km.[7] It is redder than Varuna, unlike its neutral-colored "twin" 2002 TX300, in spite of similar brightness and orbit elements.
The discovery of a satellite of 2002 UX25 was reported in IAUC 8812 on 22 February 2007.[5] The satellite was detected using the Hubble Space Telescope in August 2005.[5] The orbit of this satellite has yet to be determined. The satellite was found at 0.16 arcsec from the primary with an apparent magnitude difference of 2.5.[14] Assuming a similar albedo the magnitude suggests the satellite has a diameter of 205 ± 55 km.[6]
2002 UX25 has a perihelion (closest approach to the Sun) of 36.7 AU,[4] which it will next reach in 2065.[4] As of 2010, 2002 UX25 is 41 AU from the Sun.[12]
The Minor Planet Center (MPC) classifies 2002 UX25 as a cubewano[2] while the Deep Ecliptic Survey (DES) classifies it as scattered-extended.[3] The DES using a 10My integration (last observation: 2009-10-22) shows it with a minimum perihelion (qmin) distance of 36.3 AU.[3]
2002 UX25 has been observed 60 times with precovery images back to 1991.[4]
The Spitzer Space Telescope has estimated 2002 UX25 to have a diameter of 681 +116
−114 km,[7] and most icy objects around 400 km in diameter are believed to be spherical.[15] Mike Brown's website lists it as a highly likely dwarf planet,[16] and Mike Brown calls it a probable dwarf planet.[17] Light curve analysis has questioned whether it would truly qualify as a dwarf planet.[18][19]
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This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)