| Discovery[1] | |
|---|---|
| Discovered by | O. Oikawa |
| Discovery site | Tokyo Astronomical Obs. (389) |
| Discovery date | 17 November 1927 |
| Designations | |
| (1185) Nikko | |
Named after | Nikkō(Japanese city)[2] |
| 1927 WC · 1930 SE1 1930 SG1 · 1930 SH1 | |
| main-belt · (inner)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 86.78 yr (31,697 days) |
| Aphelion | 2.4744AU |
| Perihelion | 2.0006 AU |
| 2.2375 AU | |
| Eccentricity | 0.1059 |
| 3.35yr (1,222 days) | |
| 280.93° | |
| 0° 17m 40.2s / day | |
| Inclination | 5.7013° |
| 71.904° | |
| 1.9614° | |
| Physical characteristics | |
| Dimensions | 8.347±0.297 km[4] 11.35 km(calculated)[3] 12.56±0.83 km[5] |
| 3.781±0.0326[6] 3.78615±0.00005 h[7] 3.788±0.0326 h[6] 3.7889±0.0004 h[8] 3.79±0.01 h[9] 3.792±0.002h[8] | |
| 0.164±0.023[5] 0.20(assumed)[3] 0.370±0.041[4] | |
| S(Tholen)[1] · S(SMASS)[1] S[3] B–V = 0.923[1] U–B = 0.514[1] | |
| 11.674±0.002(R)[6] · 11.99±0.33[10] · 12.09[1][3][4][5] | |
1185 Nikko, provisional designation1927 WC, is a stonyasteroid from the inner regions of theasteroid belt, approximately 10 kilometers in diameter. It was discovered on 17 November 1927 byOkuro Oikawa at the Tokyo Astronomical Observatory, Japan.[11] The asteroid was named after the Japanese city ofNikkō.[2]
Nikko orbits the Sun in theinner main-belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,222 days). Its orbit has aneccentricity of 0.11 and aninclination of 6° with respect to theecliptic.[1]Nikko'sobservation arc begins with its first used observation taken atJohannesburg Observatory in 1930, or 3 years after its official discovery observation at Tokyo.[11]
In both theTholen andSMASS taxonomy,Nikko is a common stonyS-type asteroid.[1]
Between 2004 and 2011, several rotationallightcurves ofNikko were obtained from photometric observations taken by astronomersLaurent Bernasconi,[8] Hiromi and Hiroko Hamanowa,[8] John Menke,[12]Robert Stephens,[9] as well as at thePalomar Transient Factory in California.[6] Lightcurve analysis gave arotation period between 3.781 and 3.792 hours with a brightness variation between 0.26 and 0.50magnitude (U=3/3/3/3-/2/2).[3]
According to the survey carried out by the JapaneseAkari satellite and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Nikko measures 8.347 and 12.56 kilometers in diameter, and its surface has analbedo of 0.370 and 0.164, respectively.[4][5] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 11.35 kilometers with anabsolute magnitude of 12.09.[3]
Thisminor planet was named for the Japanese city ofNikkō, located in the Tochigi Prefecture of central Japan. The tourist resort is known for its Shinto shrine and a UNESCO World Heritage SiteNikkō Tōshō-gū. The official naming citation was published byPaul Herget inThe Names of the Minor Planets in 1955 (H 110).[2][13]
