4230 van den Bergh

4230 van den Bergh (prov. designation: 1973 ST1) is a highly elongated Hildian asteroid and member of the Schubart family from the outer regions of the asteroid belt. It was discovered on 19 September 1973, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden Observatory, on photographic plates taken by Dutch–American astronomer Tom Gehrels at the Palomar Observatory, California.[1] The assumed carbonaceous C-type asteroid asteroid has a very long rotation period of 88 hours and measures approximately 37 kilometers (23 miles) in diameter.[4] It was named for Dutch–Canadian astronomer Sidney Van den Bergh.[2]

4230 van den Bergh
van den Bergh modeled from its lightcurve
Discovery [1]
Discovered byC. J. van Houten
I. van Houten-G.
T. Gehrels
(Palomar–Leiden survey)
Discovery sitePalomar Obs.
Discovery date19 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 arc65.60 yr (23,961 d)
Aphelion4.4786 AU
Perihelion3.4219 AU
3.9502 AU
Eccentricity0.1338
7.85 yr (2,868 d)
65.499°
0° 7m 31.8s / day
Inclination3.0995°
160.47°
20.889°
Physical characteristics
Mean diameter
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]

    Orbit and classification

    van den Bergh is a member of the Schubart family (002),[5] a small family of a few hundred carbonaceous asteroids located in the dynamical region of the Hilda group.[1][4][11] It orbits the Sun in the outer 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 an eccentricity of 0.13 and an inclination of 3° with respect to the ecliptic.[3] The body's observation arc begins with a precovery taken at Palomar Observatory in November 1951, nearly 22 years prior to its official discovery observation.[1] While the asteroid was discovered during the second Palomar–Leiden Trojan survey, it did not received a "T"-prefixed survey designation.

    Naming

    This minor planet was named after Sidney Van den Bergh (born 1929), Dutch-born Canadian astronomer and former director of the Dominion Astrophysical Observatory. Van den Bergh was the vice president of the International Astronomical Union from 1976 to 1982.[1][2][12] The official naming citation was published by the Minor Planet Center on 28 May 1991 (M.P.C. 18307).[13]

    Physical characteristics

    van den Bergh is an assumed, carbonaceous C-type asteroid,[4] while its very low albedo (see below) is indicative for D- and P-types.

    Rotation period

    In August 2012, a rotational lightcurve of van den Bergh was obtained from photometric observations in the R-band by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a long rotation period of 87.918 hours with a brightness amplitude of 1.09 magnitude, 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 a slow rotator, the asteroid's period is significantly longer than that measured for most asteroids.

    Diameter and albedo

    According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, van den Bergh measures between 28.461 and 42.63 kilometers in diameter and its surface has an albedo between 0.021 and 0.050.[6][7][8]

    The Collaborative 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 an absolute magnitude of 11.7.[4]

    gollark: I mean, I have to get up at 08:30 because school requires it for stupid reasons.
    gollark: Isn't it the weekend tomorrow?
    gollark: I should check my interweb logs.
    gollark: Fascinating.
    gollark: England's not really a country.

    References
    1. "4230 van den Bergh (1973 ST1)". Minor Planet Center. Retrieved 23 May 2018.
    2. "Asteroid (4230) van den Bergh". The Royal Astronomy Society of Canada. Retrieved 23 May 2018.
    3. "JPL Small-Body Database Browser: 4230 van den Bergh (1973 ST1)" (2017-07-05 last obs.). Jet Propulsion Laboratory. Retrieved 23 May 2018.
    4. "LCDB Data for (4230) van den Bergh". Asteroid Lightcurve Database (LCDB). Retrieved 23 May 2018.
    5. "Asteroid 4230 van den Bergh". Small Bodies Data Ferret. Retrieved 23 May 2018.
    6. Grav, T.; Mainzer, A. K.; Bauer, J.; Masiero, J.; Spahr, T.; McMillan, R. S.; et al. (January 2012). "WISE/NEOWISE Observations of the Hilda Population: Preliminary Results". The Astrophysical Journal. 744 (2): 15. arXiv:1110.0283. Bibcode:2012ApJ...744..197G. doi:10.1088/0004-637X/744/2/197.
    7. Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 22 October 2019.
    8. Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 17 October 2019. (online, AcuA catalog p. 153)
    9. Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75.
    10. Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007.
    11. Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). Identification and Dynamical Properties of Asteroid Families. Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.
    12. "Individual Member – Sidney van den Bergh". IAU – International Astronomical Union. Retrieved 23 May 2018.
    13. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 23 May 2018.
    14. Sonnett, S.; Mainzer, A.; Grav, T.; Masiero, J.; Bauer, J. (February 2015). "Binary Candidates in the Jovian Trojan and Hilda Populations from NEOWISE Light Curves". The Astrophysical Journal. 799 (2): 20. arXiv:1412.1853. Bibcode:2015ApJ...799..191S. doi:10.1088/0004-637X/799/2/191.
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