| Discovery[1] | |
|---|---|
| Discovered by | Y. Väisälä |
| Discovery site | Turku Obs. |
| Discovery date | 11 October 1936 |
| Designations | |
| (1631) Kopff | |
Named after | August Kopff(astronomer)[2] |
| 1936 UC · 1926 TH 1935 FG · 1946 SA 1952 HV2 | |
| main-belt · Flora[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 90.37 yr (33,006 days) |
| Aphelion | 2.7129AU |
| Perihelion | 1.7572 AU |
| 2.2350 AU | |
| Eccentricity | 0.2138 |
| 3.34yr (1,220 days) | |
| 107.17° | |
| Inclination | 7.4943° |
| 16.826° | |
| 315.11° | |
| Physical characteristics | |
| Dimensions | 8.636±0.395 km[4] 9.58±0.21 km[5] 9.66±1.2 km[6] 9.71 km(derived)[3] |
| 6.683±0.001h[7] | |
| 0.2497±0.074[6] 0.259±0.012[5] 0.2710(derived)[3] 0.342±0.061[4] | |
| S[3] | |
| 12.1[1][3][4] · 12.2[5][6] · 12.57±0.35[8] | |
1631 Kopff (provisional designation1936 UC) is a stony Florianasteroid from the inner regions of theasteroid belt, approximately 9 kilometers in diameter. It was discovered on 11 October 1936, by Finnish astronomerYrjö Väisälä atTurku Observatory in Southwest Finland.[9][a] It was later named after German astronomerAugust Kopff.[2]
Kopff is a member of theFlora family, one of the largest collisional families of stonyS-type asteroid. It orbits the Sun in theinner main-belt at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,220 days). Its orbit has aneccentricity of 0.21 and aninclination of 7° with respect to theecliptic.[1] First identified as1926 TH atHeidelberg in 1926, the body'sobservation arc begins with its official discovery observation at Turku in 1936.[9]
In November 2003, a rotationallightcurve of Kopff was obtained from remote photometric observations at the Tenagra andTenagra II Observatories. Lightcurve analysis gave a well-definedrotation period of 6.683 hours with a brightness variation of 0.41magnitude (U=3).[7]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite, and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission, Kopff measures between 8.64 and 9.66 kilometers in diameter and its surface has analbedo between 0.2497 and 0.342.[4][5][6] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.271 and a diameter of 9.71 kilometers, with anabsolute magnitude of 12.1.[3]
Thisminor planet was named for German astronomerAugust Kopff (1882–1960). He was first an assistant toMax Wolf, and became later a prolificdiscoverer of minor planets himself. In 1924, Kopff became Director of theAstronomisches Rechen-Institut in Berlin, and, after the western section moved to Heidelberg, he also became director of theHeidelberg Observatory. Under his leadership, the thirdCatalogue of Fundamental Stars (FK3) was compiled and the work on the fourth catalogue (FK4) was initiated. The lunar craterKopff is also named in his honour.[2] The officialnaming citation was published by theMinor Planet Center on 20 February 1976 (M.P.C. 3931).[10]
