6247 Amanogawa
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| 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 | 27.45 yr (10,025 d) |
| Aphelion | 2.5286 AU |
| 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 designation 1990 WY3, is a background asteroid from the inner regions of the asteroid belt, approximately 7 kilometers (4 miles) in diameter. It was discovered on 21 November 1990, by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at the Kitami Observatory.[1] The X-type asteroid has a rotation period of 12.38 hours.[6] It was named after the Amanogawa River on the island of Hokkaido, Japan.[1]
Amanogawa is a non-family asteroid from the main belt's background population.[3] It orbits the Sun in the inner 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 an eccentricity of 0.06 and an inclination of 9° with respect to the ecliptic.[2] The body's observation arc begins with a precovery at Palomar Observatory on 14 November 1990, just one week prior to its official discovery observation at Kitami.[1]
Physical characteristics
In the SDSS-based taxonomy, Amanogawa has been characterized as an X-type asteroid.[9] It is also a generically assumed C-type asteroid.[6]
Rotation period
In September 2008, a rotational lightcurve of Amanogawa was obtained from photometric observations at the Oakley Southern Sky Observatory and Oakley Observatory. Lightcurve analysis gave a well-defined rotation period of 12.38 hours with a brightness variation of 0.48 magnitude (U=3).[8] In February 2014, astronomers at the Palomar Transient Factory measured a similar period of 12.369 hours and an amplitude of 0.38 magnitude in the R-band (U=2).[7]
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Amanogawa measures 6.722 kilometers in diameter and its surface has an albedo of 0.165.[4][5] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 11.63 kilometers based on an absolute magnitude of 13.4.[6]
