| Discovery[1] | |
|---|---|
| Discovered by | Ernest Johnson |
| Discovery site | Johannesburg Obs. |
| Discovery date | 22 August 1949 |
| Designations | |
| (3184) Raab | |
Named after | Herbert Raab[1] (Austrian astronomer) |
| 1949 QC · 1970 GR1 1975 SG · 1980 WF1 | |
| main-belt[1][2] · (middle) background[3] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 68.41yr (24,988 d) |
| Aphelion | 3.3689AU |
| Perihelion | 1.9689 AU |
| 2.6689 AU | |
| Eccentricity | 0.2623 |
| 4.36 yr (1,593 d) | |
| 269.05° | |
| 0° 13m 33.96s / day | |
| Inclination | 8.1951° |
| 97.111° | |
| 238.00° | |
| Physical characteristics | |
| 13.25 km(calculated)[4] 15.28±5.62 km[5] 17.49±0.28 km[6] 17.638±0.108 km[7] 18.38±7.54 km[8] 19.280±0.060 km[9] | |
| 274.944±2.9899 h[10] | |
| 0.036±0.004[7] 0.0470±0.0041[9] 0.05±0.04[8] 0.065±0.070[5] 0.086±0.003[6] 0.10(generic)[4] | |
| C/S(generic)[4] | |
| 12.056±0.002(R)[10] 12.10[6][9] 12.11±0.30[11] 12.2[2] 12.46[8] 12.51[4] 12.67[5] | |
3184 Raab, provisional designation1949 QC, is a dark backgroundasteroid and a potentiallyslow rotator from the central regions of theasteroid belt, approximately 17 kilometers (11 miles) in diameter. It was discovered on 22 August 1949, by South African astronomerErnest Leonard Johnson at theUnion Observatory in Johannesburg. The likelyC-type asteroid could have a longrotation period of 275 hours. It was named after Austrian amateur astronomer and software engineerHerbert Raab.[1][4]
Raab is a non-family asteroid from the main belt'sbackground population.[3] It orbits the Sun in thecentral main-belt at a distance of 2.0–3.4 AU once every 4 years and 4 months (1,593 days;semi-major axis of 2.67 AU). Its orbit has aneccentricity of 0.26 and aninclination of 8° with respect to theecliptic.[2] The body'sobservation arc begins with its official discovery observation at Johannesburg in August 1949.[1]
This asteroid'sspectral type is unknown. Based on its lowalbedo, measured by theWide-field Infrared Survey Explorer (WISE),Raab is possiblyC-type asteroid.[2]
In December 2011, a rotationallightcurve ofRaab was obtained fromphotometric observations in the R-band by astronomers at thePalomar Transient Factory in California.[10] Lightcurve analysis gave arotation period of 274.944 hours with a brightness amplitude of 0.09magnitude. However, the lightcurve is only fragmentary and could be completely wrong (U=1).[4] This makesRaab only apotentially slow rotator rather than aconfirmed one. As of 2018, no follow up observations have been published.[2][4]
According to the surveys carried out by the JapaneseAkari satellite and theNEOWISE mission of NASA's WISE telesecope,Raab measures between 15.28 and 19.280 kilometers in diameter and its surface has analbedo between 0.036 and 0.086.[5][6][7][8][9]
TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.10 – used as a generic compromise between thestony (0.20) andcarbonaceous (0.057) asteroids with semi-major axis between 2.6 and 2.7 AU – and consequently calculates a shorter diameter of 13.25 kilometers using on anabsolute magnitude of 12.51.[4]
Thisminor planet was named after Austrian amateur astronomer and software engineerHerbert Raab (born 1969), who developed theastrometric software "Astrometrica". The official naming citation was published by theMinor Planet Center on 3 May 1996 (M.P.C. 27124), following a proposal byBrian Marsden andGareth Williams.[1][12]
