| Discovery[1] | |
|---|---|
| Discovered by | C. Shoemaker |
| Discovery site | Palomar Obs. |
| Discovery date | 21 November 1984 |
| Designations | |
| (3873) Roddy | |
Named after | David Roddy (Americanastrogeologist)[2] |
| 1984 WB · 1953 XK1 | |
| Mars-crosser[1] Hungaria[3][4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 32.46 yr (11,855 days) |
| Aphelion | 2.1452AU |
| Perihelion | 1.6387 AU |
| 1.8920 AU | |
| Eccentricity | 0.1339 |
| 2.60yr (951 days) | |
| 140.78° | |
| 0° 22m 43.32s / day | |
| Inclination | 23.357° |
| 250.06° | |
| 267.60° | |
| Knownsatellites | 1(likely)[5] |
| Physical characteristics | |
| Dimensions | 5.021±0.581[6] 7.13 km(calculated)[4] 7.51±0.25 km[7] |
| 2.4782±0.09 h[8] 2.479±0.001 h[9] 2.4792±0.0001 h[10] 2.4797±0.00006 h[5] 2.480±0.001 h[11] 2.486±0.001 h[12] | |
| 0.20(assumed)[4] 0.419±0.164[6] 0.512±0.039[7] | |
| SMASS =S[1] · S[4] · L[13] | |
| 12.00[7][13] · 12.8[1] · 13.1[4][14] | |
3873 Roddy, provisional designation1984 WB, is a stony Hungarianasteroid,Mars-crosser and suspectedbinary system,[5] from the innermost regions of theasteroid belt, approximately 7 kilometers in diameter. It was discovered on 21 November 1984, by American astronomerCarolyn Shoemaker at thePalomar Observatory in California, United States.[3] It was named after American astrogeologistDavid Roddy.[2]
Roddy is a member of theHungaria family, which form theinnermost dense concentration of asteroids in theSolar System. It orbits the Sun at a distance of 1.6–2.1 AU once every 2 years and 7 months (951 days). Its orbit has aneccentricity of 0.13 and aninclination of 23° with respect to theecliptic.[1] The firstprecovery was taken at the discovering observatory in 1953, extending the asteroid'sobservation arc by 31 years prior to its discovery.[3]
In theSMASS classification,Roddy is a commonS-type asteroid. It has also been characterized as a rareL-type asteroid.[13]
According to the surveys carried out by NASA'sNEOWISE mission and the JapaneseAkari satellite, the asteroid measures 5.0 and 7.5 kilometers, and its surface has an exceptionally highalbedo of 0.419 and 0.512, respectively,[6][7] while theCollaborative Asteroid Lightcurve Link assumes a standard albedo forstony asteroids of 0.20 and calculates a diameter of 7.1 kilometers with anabsolute magnitude of 13.1.[4]
A large number of photometric observations by American astronomerBrian Warner at the Palmer Divide Observatory (716) in Colorado, were made to measure the asteroid'slightcurve. One of the best results rendered a period of2.4782 hours and a variation in brightness of 0.05 in magnitude (U=3).[15] Other lightcurve observations gave a similar period between 2.478 and 2.486 hours.[5][8][9][10][11][12]
While there is strong evidence for anasteroid moon orbitingRoddy, its existence is still uncertain as of 2016. Based on one observation/solution, the satellite has an orbital period of19.24±0.02 hours and measures about 27% of Roddy's diameter, which is slightly less than 2 kilometers (Ds/Dp ratio of0.27±0.02). However, an alternative orbital period of 23.8 hours is also possible.[5]
Thisminor planet was named in after David J. Roddy (1932–2002), an Americanastrogeologist and authority on terrestrialimpact craters at theU.S. Geological Survey. He is noted for his mathematical models ofimpact events and his studies onDevonian impact craters, as well as for using explosives for his field experiments.[2] The approved naming citation was published by theMinor Planet Center on 12 December 1989 (M.P.C. 15574).[16]
