| Discovery[1] | |
|---|---|
| Discovered by | E. Johnson |
| Discovery site | Johannesburg Obs. |
| Discovery date | 9 August 1948 |
| Designations | |
| (1731) Smuts | |
Named after | Jan Smuts (Field Marshal;PM)[2] |
| 1948 PH · 1926 TF 1931 QA · 1935 FS 1938 YB · 1941 KG 1947 LC · 1948 PP 1954 SX · 1960 WE 1966 UY | |
| main-belt · (outer)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 90.22 yr (32,954 days) |
| Aphelion | 3.5712AU |
| Perihelion | 2.7652 AU |
| 3.1682 AU | |
| Eccentricity | 0.1272 |
| 5.64yr (2,060 days) | |
| 41.052° | |
| 0° 10m 29.28s / day | |
| Inclination | 5.9328° |
| 152.48° | |
| 203.73° | |
| Physical characteristics | |
| Dimensions | 53.83 km(derived)[3] 54.71±0.98 km[4] 54.784±0.236[5] 57.491±0.432 km[6] |
| 12.5±0.7h[7] | |
| 0.0385(derived)[3] 0.0534±0.0060[6] 0.058±0.010[5] 0.059±0.003[4] | |
| C[3] | |
| 10.00[4][6] · 10.5[1][3] | |
1731 Smuts, provisional designation1948 PH, is a carbonaceousasteroid from the outer region of theasteroid belt, approximately 54 kilometers in diameter. It was discovered on 9 August 1948, by South African astronomerErnest Johnson atJohannesburg Observatory in South Africa, who named it after Field marshalJan Smuts.[2][8]
Smuts orbits the Sun in theouter main-belt at a distance of 2.8–3.6 AU once every 5 years and 8 months (2,060 days). Its orbit has aneccentricity of 0.13 and aninclination of 6° with respect to theecliptic.[1] First identified as1926 TF in Heidelberg,Smuts's first used observation was taken one month later in November 1926, extending the body'sobservation arc by 22 years prior to its official discovery observation.[8]
Smuts has been characterized as a carbonaceousC-type asteroid.[3]
In March 2008, a rotationallightcurve ofSmuts was obtained from photometric observations by French amateur astronomerRené Roy. It gave arotation period of 12.5 hours with a brightness variation of 0.8magnitude (U=2).[7]
According to the surveys carried out by the JapaneseAkari satellite and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Smuts measures between 54.71 and 57.49 kilometers in diameter, and its surface has analbedo between 0.053 and 0.059.[4][5][6] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0385 and a diameter of 53.83 kilometers based on anabsolute magnitude of 10.5.[3]
Thisminor planet was named after prominent South African and British Commonwealth statesman, Field Marshal and philosopher,Jan Smuts (1870–1950), under whom the discoverer of the asteroid fought in both World Wars.[2]
Smuts capturedGerman South-West Africa in World War I and 0.0385 the only man to sign both of the peace treaties ending the First and Second World Wars. He served as prime minister of South Africa from 1919 until 1924 and again from 1939 until 1948.[2] The officialnaming citation was published by theMinor Planet Center on 20 February 1976 (M.P.C. 3933).[9]
