| Discovery[1] | |
|---|---|
| Discovered by | H. van Gent |
| Discovery site | Johannesburg Obs. |
| Discovery date | 9 September 1934 |
| Designations | |
| (1384) Kniertje | |
Named after | Kniertje[2](fictional character) |
| 1934 RX | |
| main-belt · (middle) Eunomia[3] · Adeona[4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 83.06 yr (30,338 days) |
| Aphelion | 3.1649AU |
| Perihelion | 2.1872 AU |
| 2.6760 AU | |
| Eccentricity | 0.1827 |
| 4.38yr (1,599 days) | |
| 288.15° | |
| 0° 13m 30.36s / day | |
| Inclination | 11.858° |
| 152.86° | |
| 276.17° | |
| Physical characteristics | |
| Dimensions | 21.52±6.01 km[5] 21.72±6.93 km[6] 26.14±0.56 km[7] 26.29±0.38 km[8] 26.517±0.090 km[9] 26.59 km(derived)[3] 27.51±1.6 km[10] 29.592±0.230 km[11] |
| 9.78±0.02h[12] 9.807±0.002 h[12] 9.808±0.001 h[12] 9.824±0.001 h[13] 9.872±0.012 h[14] 12.255±0.004 h[15][a] | |
| 0.0351±0.0035[11] 0.06±0.03[6] 0.064±0.006[8] 0.066±0.003[7] 0.07±0.05[5] 0.0701(derived)[3] 0.3077±0.039[10] | |
| S(assumed, Eunomia)[3] C(assumed; Adeona)[16]: 23 | |
| 9.70[10] · 11.38[3][11] · 11.4[17] · 11.50[7][8] · 11.60[1][6] · 11.64[5] · 11.81±0.22[18] | |
1384 Kniertje, provisional designation1934 RX, is a dark Adeonianasteroid from the central regions of theasteroid belt, approximately 26 kilometers in diameter. It was discovered on 9 September 1934, by Dutch astronomerHendrik van Gent at theUnion Observatory in Johannesburg, South Africa.[19] The asteroid was named after a character in the Dutch playOp Hoop van Zegen byHerman Heijermans.[2]
Kniertje is a member of theAdeona family (505),[4] a largefamily of carbonaceous asteroids in the central main belt, named after145 Adeona. It is also dynamically classified as a member of theEunomia family (502), the largest in the intermediate main belt with more than 5,000 stony asteroids.[3][16]: 23
The asteroid orbits the Sun in thecentral asteroid belt at a distance of 2.2–3.2 AU once every 4 years and 5 months (1,599 days). Its orbit has aneccentricity of 0.18 and aninclination of 12° with respect to theecliptic.[1] The body'sobservation arc begins with its official discovery observation at Johannesburg in 1934.[19]
Kniertje'sspectral type is unknown. Although the LCDB assumes anS-type (due to its dynamical classification to the stony Eunomia family), a low albedo of 0.0701 is derived(see below) which is typical for carbonaceousC-type asteroids and in agreement with the overall spectral type of the Adeona family (505).[3][16]: 23
Several rotationallightcurves ofKniertje have been obtained from photometric observations since 2003. Lightcurve analysis gave arotation period between 9.78 and 9.872 hours with a brightness variation between 0.15 and 0.32magnitude (U=2/2/2/2/2).[12][13][14] An alternative period solution of 12.255 hours with an amplitude of 0.33 magnitude was found byBrian Warner in March 2006 (U=2).[15][a]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Kniertje measures between 21.52 and 29.592 kilometers in diameter and its surface has analbedo between 0.0351 and 0.3077.[5][6][7][8][9][10][11]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0701 and a diameter of 26.59 kilometers based on anabsolute magnitude of 11.38.[3]
Thisminor planet was named after the principal character inOp Hoop van Zegen, a play by Dutch writerHerman Heijermans (1864–1924). The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 125).[2]
