| Discovery[1] | |
|---|---|
| Discovered by | Indiana University (Indiana Asteroid Program) |
| Discovery site | Goethe Link Obs. |
| Discovery date | 14 September 1955 |
| Designations | |
| (1971) Hagihara | |
Named after | Yusuke Hagihara (astronomer)[2] |
| 1955 RD1 · 1971 TZ2 | |
| main-belt · (outer) Eos[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 59.65 yr (21,787 days) |
| Aphelion | 3.2479AU |
| Perihelion | 2.7370 AU |
| 2.9924 AU | |
| Eccentricity | 0.0854 |
| 5.18yr (1,891 days) | |
| 294.31° | |
| 0° 11m 25.44s / day | |
| Inclination | 8.6990° |
| 300.12° | |
| 120.50° | |
| Physical characteristics | |
| Dimensions | 12.289±0.156[1][4] 15±7 km(converted)[5] |
| 0.135±0.028[1][4] | |
| 12.3[6][1] | |
1971 Hagihara, provisional designation1955 RD1, is an Eoanasteroid from the outer region of theasteroid belt, approximately 12 kilometers in diameter.
It was discovered on 14 September 1955, by theIndiana Asteroid Program at theGoethe Link Observatory near Brooklyn, Indiana, United States.[6] It was later named after Japanese astronomerYusuke Hagihara.[2]
Hagihara is a member of theEos family (606), the largestasteroid family in theouter main belt consisting of nearly 10,000 asteroids.[3][7]: 23 It orbits the Sun in theouter main-belt at a distance of 2.7–3.2 AU once every 5 years and 2 months (1,891 days). Its orbit has aneccentricity of 0.09 and aninclination of 9° with respect to theecliptic.[1] The asteroid'sobservation arc begins with its discovery observation at Goethe in September 1955.[6]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Hagihara measures 12.3 kilometers in diameter and its surface has analbedo of 0.135, which is neither typical forstony nor forcarbonaceous bodies.[1][4] As of 2017, the asteroid's composition andspectral type, as well as itsrotation period and shape remain unknown.[8]
Thisminor planet was named in honour ofYusuke Hagihara (1897–1979) on the occasion of his 81st birthday. He was professor of astronomy at theUniversity of Tokyo and director of the Tokyo Observatory. He also served as vice-president of theInternational Astronomical Union and was the president of its Commission VII.
Hagihara is best known for the discussion of stability problems in celestial mechanics and his theory of libratory motions, as well as for important contributions to the study of the velocity distribution of free electrons in planetary nebulae, and his important five-volume treatise on celestial mechanics.[2] The officialnaming citation was published by theMinor Planet Center on 1 August 1978 (M.P.C. 4419).[9]
