| Discovery[1] | |
|---|---|
| Discovered by | NEAT |
| Discovery site | Palomar Obs. |
| Discovery date | 12 April 2002 |
| Designations | |
| (83982) Crantor | |
| Pronunciation | /ˈkræntɔːr/ |
Named after | Crantor(Greek mythology)[2] |
| 2002 GO9 | |
| Uranusco-orbitalcentaur[1] · distant[3] | |
| Symbol | .svg) (astrological) |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 3 | |
| Observation arc | 13.37 yr (4,882 days) |
| Aphelion | 24.862AU |
| Perihelion | 14.047 AU |
| 19.454 AU | |
| Eccentricity | 0.2780 |
| 85.81yr (31,342 days) | |
| 63.889° | |
| 0° 0m 41.4s / day | |
| Inclination | 12.770° |
| 117.40° | |
| 93.203° | |
| Physical characteristics | |
| 59±12 km[4] | |
| 13.94 h[5] | |
| 0.121±0.064[4] | |
| RR[6] B–V =1.105±0.042[7] V–R =0.761±0.039[7] | |
| 8.26[5] · 8.693±0.057(R)[8] · 8.8[1] · 9.03±0.16[4] · 9.17[9][10] | |
83982 Crantor (provisional designation2002 GO9) is acentaur in a 1:1resonance withUranus, approximately 60 kilometers (37 miles) in diameter. It was discovered on 12 April 2002, by astronomers of theNear-Earth Asteroid Tracking at thePalomar Observatory in California, United States.[3] Thisminor planet was named forCrantor from Greek mythology.[2]
Crantor orbits the Sun at a distance of 14.0–24.9 AU once every 85 years and 10 months (31,342 days). Its orbit has a semi-major axis of 19.5 AU, a moderateeccentricity of 0.28, and aninclination of 13° with respect to theecliptic.[1]
The minor planet was first observed on aprecovery taken by theSloan Digital Sky Survey on 19 March 2001. One night later, the body'sobservation arc begins with an observation by theAir Force Maui Optical Station (AMOS) atHaleakala Observatory on the island of Hawaii, more than a year prior to its official discovery observation by NEAT.[3]
Crantor was first suggested as a possible co-orbital of Uranus in 2006.[11] The body follows a complex, transienthorseshoe orbit around Uranus. Classical horseshoe orbits include theLagrangian pointsL3,L4, andL5, but Crantor's horseshoe orbit also brings it near Uranus. The motion of Crantor is mainly controlled by the influence of the Sun and Uranus, but Saturn has a significant destabilizing effect. The precession of the nodes of Crantor is accelerated by Saturn, controlling its evolution and short-term stability.[12]
Thisminor planet was named afterCrantor, aLapith fromGreek mythology. He was killed in the battle between the Lapiths and the Centaurs by Demoleon, who tore off Crantor's chest and left shoulder with a tree trunk that he had thrown atTheseus, who ducked out of the way (centaur Demoleon is not to be confused with Trojan warriorDemoleon, see18493 Demoleon).[2] The official naming citation was published by theMinor Planet Center on 15 December 2005 (M.P.C. 55724).[13]
Water ice has been detected on Crantor with a confidence of more than 3σ (99.7%).[14]
A fragmentary rotationallightcurve of Crantor was obtained from photometric observations at theSierra Nevada Observatory in Granada, Spain. Lightcurve analysis gave arotation period of 13.94 hours with a brightness amplitude of 0.14magnitude (U=1).[5]
According to the observations by theHerschel Space Telescope with itsPACS instrument, Crantor measures59±12 kilometers in diameter and its surface has analbedo of 0.121.[4] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.10 and derives a diameter of 61.59 kilometers based on anabsolute magnitude of 9.17.[10]
