Discovered by K. EndateK. Watanabe MPC designation 5692 Shirao Discovered 23 March 1992 Asteroid group Asteroid belt | Discovery date 23 March 1992 Orbits Sun | |
Alternative names 1992 FR · 1949 KK1966 FO · 1966 FS1970 CH · 1976 SN21979 HT2 · 1979 HV11985 UW2 · 1989 SO9 People also search for Sun, 4971 Hoshinohiroba | ||
5692 Shirao, provisional designation 1992 FR, is a stony Eunomia asteroid from the middle region of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 23 March 1992, by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at Kitami Observatory, Hokkaidō, Japan.
The asteroid is a member of the Eunomia family, a large group of stony S-type asteroids and the most prominent family in the intermediate main-belt. It orbits the Sun at a distance of 2.2–3.1 AU once every 4 years and 4 months (1,580 days). Its orbit has an eccentricity of 0.18 and an inclination of 12° with respect to the ecliptic. The first used precovery was taken at the U.S. Palomar Observatory in 1955, extending the asteroid's observation arc by 37 years prior to its discovery.
In June 2014, a rotational light-curve for this asteroid was obtained from photometric observations made by American astronomer Brian D. Warner at the U.S. Palmer Divide Observatory in Colorado. It gave a well-defined rotation period of 7000288780000000000♠2.8878±0.0004 hours with a brightness variation of 0.16 in magnitude (U=3). Previous light-curves were obtained by French astronomer René Roy (7000290000000000000♠2.90±0.01 hours, Δ 0.13 mag, U=2) in June 2001, by American astronomer Donald P. Pray (7000288600000000000♠2.886±0.002 hours, Δ 0.12 mag, U=2) in March 2005, and by astronomers Dominique Suys, Hugo Riemis and Jan Vantomme (7000290000000000000♠2.90±0.01 hours, Δ 0.15 mag, U=2+) in September 2006.
According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer and its subsequent NEOWISE mission, the asteroid measures between 9.5 and 9.8 kilometers in diameter and its surface has an albedo of 0.22, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo of 0.21 – derived from 15 Eunomia, the largest member and namesake of this asteroid family – and calculates a diameter of 9.2 kilometers.
The minor planet was named after Motomaro Shirao (b. 1953), a Japanese geologist and astrophotographer, who is known for his photographs of volcanoes and lunar geological features. Naming citation was published on 4 April 1996 (M.P.C. 26930).