| Discovery[1] | |
|---|---|
| Discovered by | K. Endate K. Watanabe |
| Discovery site | Kitami Obs. |
| Discovery date | 21 November 1990 |
| Designations | |
| (6247) Amanogawa | |
Named after | Amanogawa River[1] (Japanese river) |
| 1990 WY3 · 1992 FR1 | |
| main-belt[1][2] · (inner) background[3] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 27.45yr (10,025 d) |
| Aphelion | 2.5286AU |
| Perihelion | 2.2604 AU |
| 2.3945 AU | |
| Eccentricity | 0.0560 |
| 3.71 yr (1,353 d) | |
| 168.98° | |
| 0° 15m 57.6s / day | |
| Inclination | 8.5728° |
| 105.57° | |
| 287.33° | |
| Physical characteristics | |
| 6.722±0.098 km[4][5] 11.63 km(calculated)[6] | |
| 12.369±0.0107 h[7] 12.38±0.02 h[8] | |
| 0.057(assumed)[6] 0.165±0.018[4][5] | |
| C(assumed)[6] X(SDSS-MOC)[9] | |
| 13.2[5] 13.288±0.006(R)[7] 13.3[2] 13.4[6] | |
6247 Amanogawa, provisional designation1990 WY3, is a backgroundasteroid from the inner regions of theasteroid belt, approximately 7 kilometers (4 miles) in diameter. It was discovered on 21 November 1990, by Japanese amateur astronomersKin Endate andKazuro Watanabe at theKitami Observatory.[1] TheX-type asteroid has arotation period of 12.38 hours.[6] It was named after theAmanogawa River on the island of Hokkaido, Japan.[1]
Amanogawa is a non-family asteroid from the main belt'sbackground population.[3] It orbits the Sun in theinner asteroid belt at a distance of 2.3–2.5 AU once every 3 years and 9 months (1,353 days;semi-major axis of 2.39 AU). Its orbit has aneccentricity of 0.06 and aninclination of 9° with respect to theecliptic.[2] The body'sobservation arc begins with aprecovery atPalomar Observatory on 14 November 1990, just one week prior to its official discovery observation at Kitami.[1]
In theSDSS-based taxonomy,Amanogawa has been characterized as anX-type asteroid.[9] It is also a generically assumedC-type asteroid.[6]
In September 2008, a rotationallightcurve ofAmanogawa was obtained fromphotometric observations at theOakley Southern Sky Observatory andOakley Observatory. Lightcurve analysis gave a well-definedrotation period of 12.38 hours with a brightness variation of 0.48magnitude (U=3).[8] In February 2014, astronomers at thePalomar Transient Factory measured a similar period of 12.369 hours and an amplitude of 0.38 magnitude in the R-band (U=2).[7]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Amanogawa measures 6.722 kilometers in diameter and its surface has analbedo of 0.165.[4][5] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for acarbonaceous asteroid of 0.057 and calculates a diameter of 11.63 kilometers based on anabsolute magnitude of 13.4.[6]
Thisminor planet was named after the JapaneseAmanogawa River that through the town ofKaminokuni on the island of Hokkaido. "Amanogawa" also means "Milky Way" in Japanese.[1] The official naming citation was published by theMinor Planet Center on 22 February 1997 (M.P.C. 29146).[10]
