Discovery date 24 April 1985 Discovered 24 April 1985 | MPC designation 4151 Alanhale Orbits Sun Asteroid group Asteroid belt | |
Discovered by C. S. ShoemakerE. M. Shoemaker Alternative names 1985 HV1 · 1968 HD1976 SO1 · 1979 FX11982 SZ4 · 1985 JX Discoverers Carolyn S. Shoemaker, Henri Debehogne, Eugene Merle Shoemaker Similar Sun, Comet Hale–Bopp, 3554 Amun, Comet Shoemaker–Levy 9, 129P/Shoemaker–Levy |
4151 Alanhale, provisional designation 1985 HV1, is a carbonaceous Themistian asteroid from the outer region of the asteroid belt, approximately 19 kilometers in diameter. It was discovered by the American astronomer couple Carolyn and Eugene Shoemaker at the U.S. Palomar Observatory, California, on 24 April 1985.
The dark C-type asteroid is a member of the Themis family, a dynamical family of outer-belt asteroids with nearly coplanar ecliptical orbits. It orbits the Sun at a distance of 2.7–3.6 AU once every 5 years and 7 months (2,039 days). Its orbit has an eccentricity of 0.14 and an inclination of 1° with respect to the ecliptic. The first precovery was taken at Zimmerwald Observatory in 1968, extending the asteroid's observation arc by 17 years prior to its discovery.
A rotational light-curve of this asteroid was obtained from photometric observations made at the U.S. Palomar Transient Factory in October 2010. The fragmentary light-curve gave a rotation period of 7001119177000000000♠11.9177±0.0047 hours with a low brightness variation of 0.07 in magnitude (U=1).
According to the surveys carried out by NASA's spaced-based Wide-field Infrared Survey Explorer and its subsequent NEOWISE mission, the asteroid measures 19.5 and 22.7 kilometers in diameter, respectively, with a corresponding albedo of 0.07 and 0.05. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.08 and calculates a smaller diameter of 15.4 kilometers, based on an absolute magnitude of 12.43.
The minor planet was named in honor of American astronomer Alan Hale (b. 1958), co-discoverer of comet Hale–Bopp. 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 performed asteroid occultation. Hale has promoted the study of small Solar System bodies in articles and in his astronomy lectures. Naming citation was published on 28 April 1991 (M.P.C. 18139).