_van_den_Bergh.png) van den Bergh modeled from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | C. J. van Houten I. van Houten-G. T. Gehrels (Palomar–Leiden survey) |
| Discovery site | Palomar Obs. |
| Discovery date | 19 September 1973 |
| Designations | |
| (4230) van den Bergh | |
Named after | Sidney Van den Bergh[1][2] (Dutch–Canadian astronomer) |
| 1973 ST1 · 1978 JB2 1979 OD | |
| main-belt · (outer)[3] Hilda[1][4] · Schubart[5] | |
| Orbital characteristics[3] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 65.60yr (23,961 d) |
| Aphelion | 4.4786AU |
| Perihelion | 3.4219 AU |
| 3.9502 AU | |
| Eccentricity | 0.1338 |
| 7.85 yr (2,868 d) | |
| 65.499° | |
| 0° 7m 31.8s / day | |
| Inclination | 3.0995° |
| 160.47° | |
| 20.889° | |
| Physical characteristics | |
| 28.461±0.777 km[6] 37.75±2.9 km[7] 42.63±2.24 km[8] | |
| 87.918±0.4071 h[9] | |
| 0.021±0.002[8] 0.0259±0.005[7] 0.050±0.002[6] | |
| C(assumed)[4] | |
| 11.70[3][4][8] 11.807±0.007(R)[9] 11.81±0.10[10] | |
4230 van den Bergh (prov. designation:1973 ST1) is a highly elongatedHildian asteroid and member of theSchubart family from the outer regions of theasteroid belt. It was discovered on 19 September 1973, by Dutch astronomer coupleIngrid andCornelis van Houten at Leiden Observatory, on photographic plates taken by Dutch–American astronomerTom Gehrels at thePalomar Observatory, California.[1] The assumed carbonaceousC-type asteroid has a very longrotation period of 88 hours and measures approximately 37 kilometers (23 miles) in diameter.[4] It was named for Dutch–Canadian astronomerSidney Van den Bergh.[2]
van den Bergh is a member of theSchubart family (002),[5] a smallfamily of a few hundred carbonaceous asteroids located in the dynamical region of theHilda group.[1][4][11] It orbits the Sun in theouter main-belt at a distance of 3.4–4.5 AU once every 7 years and 10 months (2,868 days;semi-major axis of 3.95 AU). Its orbit has aneccentricity of 0.13 and aninclination of 3° with respect to theecliptic.[3] The body'sobservation arc begins with aprecovery taken at Palomar Observatory in November 1951, nearly 22 years prior to its official discovery observation.[1] While the asteroid was discovered during the secondPalomar–Leiden Trojan survey, it did not receive a "T"-prefixedsurvey designation.
Thisminor planet was named afterSidney Van den Bergh (born 1929), Dutch-born Canadian astronomer and former director of theDominion Astrophysical Observatory. Van den Bergh was the vice president of theInternational Astronomical Union from 1976 to 1982.[1][2][12] The official naming citation was published by theMinor Planet Center on 28 May 1991 (M.P.C. 18307).[13]
van den Bergh is an assumed, carbonaceousC-type asteroid,[4] while its very low albedo(see below) is indicative forD- andP-types.
In August 2012, a rotationallightcurve ofvan den Bergh was obtained fromphotometric observations in the R-band by astronomers at thePalomar Transient Factory in California. Lightcurve analysis gave a longrotation period of 87.918 hours with a brightness amplitude of 1.09magnitude, indicative of an elongated, non-spherical shape (U=2).[9] A similarly strong brightness variation of 1.15 magnitude was measured in 2015.[14] While not being aslow rotator, the asteroid's period is significantly longer than that measured for most asteroids.
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,van den Bergh measures between 28.461 and 42.63 kilometers in diameter and its surface has analbedo between 0.021 and 0.050.[6][7][8]
TheCollaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0259 and a diameter of 37.75 kilometers based on anabsolute magnitude of 11.7.[4]
