Discovered by K. EndateK. Watanabe MPC designation 4585 Ainonai Discovered 16 May 1990 Orbits Sun Asteroid group Asteroid belt | Discovery date 16 May 1990 Minor planet category main-belt · (middle) Absolute magnitude 12.9 | |
Named after Ainonai, near Kitami(Japanese town) Alternative names 1990 KQ · 1972 LU1978 WL12 · 1981 LC People also search for 4263 Abashiri, 4401 Aditi, 5692 Shirao | ||
4585 Ainonai, provisional designation 1990 KQ, is a carbonaceous asteroid from the middle region of the asteroid belt, about 15 kilometers in diameter. It was discovered on 16 May 1990, by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at the Kitami Observatory in eastern Hokkaidō, Japan.
The dark C-type asteroid orbits the Sun at a distance of 2.1–3.4 AU once every 4 years and 6 months (1,653 days). Its orbit has an eccentricity of 0.24 and an inclination of 11° with respect to the ecliptic. The first precovery was obtained at Crimea–Nauchnij in 1972, extending the asteroid's observation arc by 18 years prior to its discovery.
A rotational light-curve was obtained from photometric observation made at the Via Capote Observatory, California, in June 2008. It showed a rotation period of 7001383100000000000♠38.31±0.05 hours with a brightness amplitude of 0.30 in magnitude (U=3-) According to observations from the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, the asteroid has an albedo of 0.11 with a corresponding diameter of 10.9 kilometers. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 15.3 kilometers, based on an absolute magnitude of 12.8.
The minor planet is named after Ainonai, a small Japanese town located near Kitami in eastern Hokkaidō. The minor planets 3785 Kitami and 3720 Hokkaido are named after these two places. Naming citation was published on 21 November 1991 (M.P.C. 19338).