| Discovery[1] | |
|---|---|
| Discovered by | C. Shoemaker |
| Discovery site | Palomar Obs. |
| Discovery date | 17 August 1988 |
| Designations | |
| (4827) Dares | |
| Pronunciation | /ˈdɛəriːz/[2] |
Named after | Dares(Greek mythology)[1] |
| 1988 QE | |
| Jupiter trojan[1][3] Trojan[4] · background[5] | |
| Adjectives | Daretian |
| Orbital characteristics[3] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 63.49yr (23,191 d) |
| Aphelion | 5.3517AU |
| Perihelion | 4.8903 AU |
| 5.1210 AU | |
| Eccentricity | 0.0451 |
| 11.59 yr (4,233 d) | |
| 119.05° | |
| 0° 5m 6.36s / day | |
| Inclination | 7.7056° |
| 242.04° | |
| 170.69° | |
| Jupiter MOID | 0.0037 AU |
| TJupiter | 2.9800 |
| Physical characteristics | |
| 42.77±0.26 km[6] 44.22 km(calculated)[7] | |
| 18.995±0.028 h[8] | |
| 0.057(assumed)[7] 0.067±0.007[6] | |
| D(Pan-STARRS)[7][9] D(SDSS-MOC)[10][11] | |
| 10.4[6] 10.5[1][3][7] 10.88±0.01[9] | |
4827 Dares/ˈdɛəriːz/ is a largerJupiter trojan from theTrojan camp, approximately 43 kilometers (27 miles) in diameter. It was discovered on 17 August 1988 by American astronomerCarolyn Shoemaker at thePalomar Observatory in California.[1] The darkD-type asteroid has arotation period of 19.0 hours.[7] It was named afterDares from Greek mythology.[1]
Dares is a dark Jovianasteroid in a 1:1orbital resonance with Jupiter. It is located in the traileringTrojan camp at the Gas Giant'sL5Lagrangian point, 60° behind on its orbit(seeTrojans in astronomy). It is also a non-family asteroid of theJovian background population.[5] It orbits the Sun at a distance of 4.9–5.4 AU once every 11 years and 7 months (4,233 days;semi-major axis of 5.12 AU). Its orbit has aneccentricity of 0.05 and aninclination of 8° with respect to theecliptic.[3]
The body'sobservation arc begins with aprecovery at Palomar in November 1954, almost 34 years prior to its official discovery observation.[1]
In theSDSS-based taxonomy,Dares is a darkD-type asteroid.[10][11] It is also characterized as a D-type byPan-STARRS' survey.[7][9]
In February 1994, a rotationallightcurve ofDares was obtained over five nights of observation byStefano Mottola and Anders Erikson using theESO 1-metre telescope atLa Silla Observatory in Chile. Lightcurve analysis showed a well-definedrotation period of18.995±0.028 hours with a brightness variation of 0.24magnitude (U=3).[7][8]
In October 2013,photometric observations in the R-band by astronomers at thePalomar Transient Factory in California gave a concurring period of 18.967 hours with an amplitude of 0.23 magnitude (U=2).[7][12]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Dares measures 42.77 kilometers in diameter and its surface has analbedo of 0.067,[6] while theCollaborative Asteroid Lightcurve Link assumes a standard albedo for acarbonaceous asteroid of 0.057 and calculates a diameter of 44.22 kilometers based on anabsolute magnitude of 10.5.[7]
Thisminor planet was named by the discoverer fromGreek mythology after the TrojanDares, one ofAeneas' wandering companions (Aeneads) who were not killed or enslaved by the end of theTrojan War.[1] The official naming citation was published by theMinor Planet Center on 25 August 1991 (M.P.C. 18647).[13]
