| Discovery[1] | |
|---|---|
| Discovered by | C. S. Shoemaker E. M. Shoemaker |
| Discovery site | Palomar Obs. |
| Discovery date | 24 April 1985 |
| Designations | |
| (4151) Alanhale | |
Named after | Alan Hale(astronomer)[2] |
| 1985 HV1 · 1968 HD 1976 SO1 · 1979 FX1 1982 SZ4 · 1985 JX | |
| main-belt · Themis[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 48.95 yr (17,878 days) |
| Aphelion | 3.5904AU |
| Perihelion | 2.7017 AU |
| 3.1461 AU | |
| Eccentricity | 0.1412 |
| 5.58yr (2,038 days) | |
| 346.46° | |
| 0° 10m 35.76s / day | |
| Inclination | 1.0079° |
| 67.051° | |
| 75.088° | |
| Physical characteristics | |
| Dimensions | 15.37 km(calculated)[3] 19.526±0.269 km[4][5] 22.66±0.59 km[6] |
| 11.9177±0.0047h[7] | |
| 0.045±0.006[5][6] 0.0734±0.0099[4] 0.08(assumed)[3] | |
| C[3][8] | |
| 11.976±0.003(R)[7] · 12.0[4] · 12.20[6] · 12.3[1] · 12.43[3] · 12.78±0.21[8] | |
4151 Alanhale, provisional designation1985 HV1, is a carbonaceous Themistianasteroid from the outer region of theasteroid belt, approximately 19 kilometers in diameter. It was discovered by the American astronomer coupleCarolyn andEugene Shoemaker at the U.S.Palomar Observatory, California, on 24 April 1985.[9] It was named for American astronomerAlan Hale.[2]
Alanhale is a member of theThemis family, a dynamical family of outer-belt asteroids with nearly coplanarecliptical orbits. It orbits the Sun in theouter main-belt at a distance of 2.7–3.6 AU once every 5 years and 7 months (2,038 days). Its orbit has aneccentricity of 0.14 and aninclination of 1° with respect to the ecliptic.[1] It was first identified as1968 HD atZimmerwald Observatory in 1968, extending the body'sobservation arc by 17 years prior to its official discovery observation at Palomar.[9]
Alanhale has been characterized as a darkC-type asteroid byPanSTARRS' photometric survey.[3][8]
A rotationallightcurve ofAlanhale was obtained from photometric observations made at the U.S.Palomar Transient Factory in October 2010. The fragmentary lightcurve gave arotation period of11.9177±0.0047 hours with a low brightness variation of 0.07 inmagnitude (U=1).[7]
According to the surveys carried out by NASA's spaced-basedWide-field Infrared Survey Explorer and its subsequentNEOWISE mission,Alanhale measures 19.5 and 22.7 kilometers in diameter, respectively, with a correspondingalbedo of 0.07 and 0.05.[4][5][6] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.08 and calculates a smaller diameter of 15.4 kilometers with anabsolute magnitude of 12.43.[3]
Thisminor planet was named in honor of American astronomerAlan Hale (born 1958), co-discoverer ofcomet Hale–Bopp.[2]
His precise visual observations include more than 130 comets, several at more than one apparition, and both, magnitude estimates and confirmations of discoveries. He has also skillfully estimated the magnitudes of the near-Earth objects,4179 Toutatis and(99907) 1989 VA, and has performedasteroid occultation. Hale has promoted the study of small Solar System bodies in articles and in his astronomy lectures.[2] The official naming citation was published by theMinor Planet Center on 28 April 1991 (M.P.C. 18139).[10]
