5692 Shirao
Asteroid From Wikipedia, the free encyclopedia
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.[10] The asteroid was later named for Japanese geologist and astrophotographer Motomaro Shirao.[2]
| Discovery [1] | |
|---|---|
| Discovered by | K. Endate K. Watanabe |
| Discovery site | Kitami Obs. |
| Discovery date | 23 March 1992 |
| Designations | |
| (5692) Shirao | |
Named after | Motomaro Shirao (geologist, photographer)[2] |
| 1992 FR · 1949 KK 1966 FO · 1966 FS 1970 CH · 1976 SN2 1979 HT2 · 1979 HV1 1985 UW2 · 1989 SO9 | |
| main-belt · Eunomia [3] | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 67.83 yr (24,776 days) |
| Aphelion | 3.1373 AU |
| Perihelion | 2.1723 AU |
| 2.6548 AU | |
| Eccentricity | 0.1818 |
| 4.33 yr (1,580 days) | |
| 287.13° | |
| 0° 13m 40.44s / day | |
| Inclination | 11.931° |
| 181.78° | |
| 44.251° | |
| Physical characteristics | |
| Dimensions | 9.17 km (calculated)[3] 9.548±0.155[4] 9.75±0.30 km[5] 9.811±0.063 km[6] |
| 2.886±0.002 h[7] 2.8878±0.0004 h[a] 2.90±0.02 h (ii)[8] | |
| 0.21 (assumed)[3] 0.2218±0.0290[6] 0.223±0.030[4][5] | |
| S [3][9] | |
| 12.3[5][6] · 12.47±0.25[9] · 12.5[1][3] | |
Orbit and classification
Shirao is a member of the Eunomia family, a large group of stony asteroids and the most prominent family in the intermediate main-belt. It orbits the Sun in the central main-belt 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.[1]
In 1949, it was first identified as 1949 KK at Goethe Link Observatory. The body's observation arc begins in 1955, with a precovery at Palomar Observatory, 37 years prior to its official discovery observation at Kitami.[10]
Physical characteristics
Rotation period
In June 2014, a rotational lightcurve of Shirao was obtained from photometric observations made by American astronomer Brian Warner at his Palmer Divide Observatory (716) in Colorado. It gave a well-defined rotation period of 2.8878 hours with a brightness variation of 0.16 magnitude (U=3).[a]
Previous lightcurves were obtained by French astronomer René Roy (2.90 hours, Δ 0.13 mag, U=2) in June 2001,[8] by American astronomer Donald P. Pray (2.886 hours, Δ 0.12 mag, U=2) in March 2005,[7] and by astronomers Dominique Suys, Hugo Riemis and Jan Vantomme (2.90 hours, Δ 0.15 mag, U=2+) in September 2006.[3][8]
Diameter and albedo
According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer and its subsequent NEOWISE mission, Shirao measures between 9.5 and 9.8 kilometers in diameter and its surface has an albedo of 0.22,[4][5][6] 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.[3]
Naming
This minor planet was named after Motomaro Shirao (born 1953), a Japanese geologist and astrophotographer, who is known for his photographs of volcanoes and lunar geological features.[2] The official naming citation was published by the Minor Planet Center on 4 April 1996 (M.P.C. 26930).[11]
Notes
- Warner (2014l) web: rotation period 2.8878±0.0004 hours with a brightness amplitude of 0.16 mag. Summary figures for (5692) Shirao at Collaborative Asteroid Lightcurve Link (CALL) and (2014MPBu...41..235P)
References
External links
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