4217 Engelhardt
4217 Engelhardt, provisional designation 1988 BO2, is a stony Phocean asteroid and a potentially binary system from the inner regions of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 24 January 1988, by American astronomer Carolyn Shoemaker at Palomar Observatory in California, and later named after German mineralogist Wolf von Engelhardt.[12]
| Discovery [1] | |
|---|---|
| Discovered by | C. Shoemaker |
| Discovery site | Palomar Obs. |
| Discovery date | 24 January 1988 |
| Designations | |
| (4217) Engelhardt | |
Named after | Wolf von Engelhardt (German mineralogist)[2] |
| 1988 BO2 · 1944 RL 1951 RY1 · 1970 AA | |
| main-belt · Phocaea [3][4] | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 72.73 yr (26,563 days) |
| Aphelion | 2.8045 AU |
| Perihelion | 1.8246 AU |
| 2.3145 AU | |
| Eccentricity | 0.2117 |
| 3.52 yr (1,286 days) | |
| 272.23° | |
| 0° 16m 47.64s / day | |
| Inclination | 23.129° |
| 355.44° | |
| 348.79° | |
| Known satellites | 1 (P: 36.03 h)[5][a] |
| Physical characteristics | |
| Dimensions | 7.34±1.36 km[6] 8.742±0.356 km[7][8] 9.16±1.0 km[9] 9.24 km (derived)[3] |
| 3.066±0.001 h[10] 3.0661±0.0002 h[5][a] | |
| 0.2108±0.052[9] 0.231±0.046[7][8] 0.2489 (derived)[3] 0.37±0.17[6] | |
| S [3][11] | |
| 12.10±0.67[11] · 12.20[6] · 12.3[1][3] · 12.50[7][9] | |
Classification and orbit edit
Engelhardt is a stony S-type asteroid and a member of the Phocaea family (701).[4] It orbits the Sun in the inner main-belt at a distance of 1.8–2.8 AU once every 3 years and 6 months (1,286 days). Its orbit has an eccentricity of 0.21 and an inclination of 23° with respect to the ecliptic.[1]
It was first identified as 1944 RL at Turku Observatory in 1944, extending the body's observation arc by 44 years prior to its official discovery observation at Palomar.[12] It will pass about 0.0017 AU (250,000 km) from Earth threatening asteroid (29075) 1950 DA in 2736.[13]
Physical characteristics edit
Lightcurves edit
In November 2004, a rotational lightcurve of Engelhardt was obtained from photometric observations by American astronomer Brian Warner at this Palmer Divide Observatory in Colorado.[a] Lightcurve analysis gave a well-defined rotation period of 3.066 hours with a brightness amplitude of 0.16 magnitude (U=3).[10]
In December 2011, a follow-up observation by Warner gave a period of 3.0661 hours with 0.18 amplitude (U=3).[5] Due to a couple of supposed occultation and eclipsing events, Warner also suspects that Engelhardt might by a binary system with a minor-planet moon orbiting it every 36.03 hours. The result, however, is far from conclusive.[a]
Diameter and albedo edit
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Engelhardt measures between 7.34 and 9.16 kilometers in diameter and its surface has an albedo between and 0.231 and 0.37.[7] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.2489 and a diameter of 9.24 kilometers with on an absolute magnitude of 12.3.[3]
Naming edit
Baltic German geologist and mineralogist Wolf von Engelhardt (1910–2008), expert on impact craters and related mineral metamorphism. He was a professor at the University of Tübingen and a longtime director of its Institute of Mineralogy and Petrography.[2] The approved naming citation was published by the Minor Planet Center on 27 June 1991 (M.P.C. 18456).[14]
Notes edit
- ^ a b c d Lightcurve plot of (4217) Engelhardt, at the Palmer Divide Observatory, by B. D. Warner (2011). The first plot gives a rotation period of 3.0661 hours. The second plot has that period subtracted and gives a possible orbital period of 36.03 hours for the presumed satellite.
References edit
- ^ a b c d "JPL Small-Body Database Browser: 4217 Engelhardt (1988 BO2)" (2017-06-05 last obs.). Jet Propulsion Laboratory. Retrieved 4 July 2017.
- ^ a b Schmadel, Lutz D. (2007). "(4217) Engelhardt". Dictionary of Minor Planet Names – (4217) Engelhardt. Springer Berlin Heidelberg. p. 361. doi:10.1007/978-3-540-29925-7_4182. ISBN 978-3-540-00238-3.
- ^ a b c d e f "LCDB Data for (4217) Engelhardt". Asteroid Lightcurve Database (LCDB). Retrieved 4 April 2017.
- ^ a b "Asteroid 4217 Engelhardt – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 27 October 2019.
- ^ a b c Warner, Brian D. (April 2012). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2011 September - December". The Minor Planet Bulletin. 39 (2): 69–80. Bibcode:2012MPBu...39...69W. ISSN 1052-8091. Retrieved 4 April 2017.
- ^ a b c Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 4 April 2017.
- ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
- ^ a b Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 4 April 2017.
- ^ a b c 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.
- ^ a b Warner, Brian D. (June 2005). "Asteroid lightcurve analysis at the Palmer Divide Observatory - fall 2004". The Minor Planet Bulletin. 32 (2): 29–32. Bibcode:2005MPBu...32...29W. ISSN 1052-8091. Retrieved 4 April 2017.
- ^ a b 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. Retrieved 4 April 2017.
- ^ a b "4217 Engelhardt (1988 BO2)". Minor Planet Center. Retrieved 4 April 2017.
- ^ Giorgini, J. D.; Ostro, S. J.; Benner, L. A. M.; Chodas, P. W.; Chesley, S. R.; Hudson, R. S.; et al. (April 2002). (PDF). Science. 296 (5565): 132–136. Bibcode:2002Sci...296..132G. doi:10.1126/science.1068191. PMID 11935024. Archived from the original (PDF) on 4 July 2008. Retrieved 4 April 2017.
- ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 4 April 2017.
External links edit
- Asteroid Lightcurve Database (LCDB), query form (info 16 December 2017 at the Wayback Machine)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 4217 Engelhardt at AstDyS-2, Asteroids—Dynamic Site
- Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
- 4217 Engelhardt at the JPL Small-Body Database