| Discovery | |
|---|---|
| Discovered by | R. H. McNaught |
| Discovery site | Siding Spring Obs. |
| Discovery date | 18 February 1991 |
| Designations | |
| (5335) Damocles | |
| Pronunciation | /ˈdæməkliːz/[1] |
Named after | Damocles(Greek mythology)[2] |
| 1991 DA | |
| distant[3] centaur[4] · damocloid[5] | |
| Adjectives | Damoclean (/dæməˈkliːən/)[6] |
| Symbol | .svg) (astrological) |
| Orbital characteristics[4] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 4 | |
| Observation arc | 1.51 yr (551 days) |
| Aphelion | 22.078 AU |
| Perihelion | 1.5741 AU |
| 11.826 AU | |
| Eccentricity | 0.8669 |
| 40.67 Jyr (14,854 days) | |
| 236.35° | |
| 0° 1m 27.12s / day | |
| Inclination | 61.875° |
| 314.14° | |
| 191.26° | |
| Mars MOID | 0.05787 AU[3] |
| TJupiter | 1.149 |
| Physical characteristics | |
| Dimensions | ~ 10 km[7] |
| 26.56[8] | |
| 13.3[4][8] | |
(5335) Damocles/ˈdæməkliːz/, provisional designation1991 DA, is acentaur and the namesake of thedamocloids, a group ofminor planets which may be inactive nuclei of theHalley-type andlong-period comets. It was discovered on 18 February 1991, by Australian astronomerRobert McNaught atSiding Spring Observatory in Australia. It is named afterDamocles, a figure ofGreek mythology.[2]
When Damocles was discovered, it was found to be on anorbit completely different from all others known. Damocles's orbit reached from inside theaphelion ofMars to as far asUranus. It seemed to be in transition from a near-circularouter Solar System orbit to an eccentric orbit taking it to theinner Solar System.[9]Duncan Steel, Gerhard Hahn, Mark Bailey, andDavid Asher carried out projections of its long-term dynamical evolution, and found a good probability that it will become anEarth-crosser asteroid, and may spend a quarter of its life in such an orbit. Damocles has a stable orbit for tens of thousands of years before and after the present, because its highly inclined orbit does not take it nearJupiter orSaturn.[10][11]
There is some speculation that Damocles may have ameteor shower associated with it on Mars from the direction ofDraco.[12] The object has a Marsminimum orbit intersection distance (Mars MOID) of 0.057 AU (8,500,000 km; 5,300,000 mi) and a Uranus MOID of 0.3 AU (45,000,000 km; 28,000,000 mi).[3]
As of 2019[update], Damocles is 19.6 AU from the Sun with anapparent magnitude of 26.3.[8] It reached its furthest point from the Sun in 2011.
The adjectival form is Damoclean,/dæməˈkliːən/.[6] The official naming citation was published by theMinor Planet Center on 1 September 1993 (M.P.C. 22508).[13]
