54 Alexandra is a carbonaceous asteroid from the intermediate asteroid belt, approximately 155 kilometers in diameter. It was discovered by German-French astronomer Hermann Goldschmidt on 10 September 1858, and named after the German explorer Alexander von Humboldt; it was the first asteroid to be named after a male.[7]
| light curve | |
| Discovery[1] | |
|---|---|
| Discovered by | H. Goldschmidt |
| Discovery date | 10 September 1858 |
| Designations | |
| (54) Alexandra | |
| Pronunciation | /ˌælɪɡˈzændrə, –ˈzɑːn-/ AL-ig-ZA(H)N-drə[2] |
Named after | Alexander von Humboldt (German explorer) |
| Main belt | |
| Adjectives | Alexandrian |
| Orbital characteristics | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion | 485.483 Gm (3.245 AU) |
| Perihelion | 326.043 Gm (2.179 AU) |
| 405.763 Gm (2.712 AU) | |
| Eccentricity | 0.196 |
| 1,631.620 d (4.47 a) | |
| 103.809° | |
| Inclination | 11.804° |
| 313.446° | |
| 345.594° | |
| Physical characteristics | |
| Dimensions | 160 × 135 km (± 1 km) |
| 154.137 km[1] | |
| Mass | (6.16±3.50)×1018 kg[3] |
Mean density | 3.50±2.11 g/cm3[3] |
| 18.14 h[4] | |
Pole ecliptic latitude | 155°±4°[5] |
Pole ecliptic longitude | 17°±3°[5] |
| 0.056[1][6] | |
| Tholen = C [1] SMASS = C [1] | |
| 7.66[1] | |
Photometric observations of this asteroid during 1990–92 gave a light curve with a period of 18.14 ± 0.04 hours and a brightness variation of 0.10 in magnitude.[4] Alexandra has been studied by radar.[9] It was the namesake and largest member of the former Alexandra asteroid family; a dynamic group of C-type asteroids that share similar orbital elements. Other members included 70 Panopaea and 145 Adeona.[10] 145 Adeona was subsequently assigned to the Adeona family, with Alexandra and Panopaea being dropped.[11]
- ^ a b c d e f Yeomans, Donald K. “54 Alexandra”. JPL Small-Body Database Browser. NASA Jet Propulsion Laboratory. Retrieved 7 April 2013.
- ^ “Alexandra”. Lexico UK English Dictionary. Oxford University Press. Archived from the original on 22 March 2020.“Alexandra”. Dictionary.com Unabridged (Online). n.d.
- ^ a b c Carry, B. (December 2012), “Density of asteroids”, Planetary and Space Science, vol. 73, pp. 98–118, arXiv:1203.4336, Bibcode:2012P&SS…73…98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
- ^ a b Belskaya, I. N.; et al. (November 1993), “Physical Studies of Asteroids. Part XXVII. Photoelectric Photometry of Asteroids 14 Irene, 54 Alexandra and 56 Melete”, Astronomy and Astrophysics Supplement, vol. 101, no. 3, pp. 507–511, Bibcode:1993A&AS..101..507B.
- ^ a b Hanuš, J.; et al. (May 2017), “Volumes and bulk densities of forty asteroids from ADAM shape modeling”, Astronomy & Astrophysics, 601: 41, arXiv:1702.01996, Bibcode:2017A&A…601A.114H, doi:10.1051/0004-6361/201629956, A114.
- ^ “Asteroid Data Sets”. Archived from the original on 17 December 2009. Retrieved 12 January 2007.
- ^ Schmadel, Lutz D. (2003), Dictionary of Minor Planet Names (5th ed.), Springer, p. 20, ISBN 3642297188.
- ^ D.W. Dunham, “Upcoming Asteroid Occultations”, Sky & Telescope, June, 2006, p. 63.
- ^ “Radar-Detected Asteroids and Comets”. NASA/JPL Asteroid Radar Research. Retrieved 30 October 2011.
- ^ Williams, J. G. (March 1988), “The Unusual Alexandra Family”, Abstracts of the Lunar and Planetary Science Conference, vol. 19, pp. 1277–1278, Bibcode:1988LPI….19.1277W.
- ^ Zappala, Vincenzo; et al. (December 1990), “Asteroid families. I – Identification by hierarchical clustering and reliability assessment”, Astronomical Journal, vol. 100, pp. 2030–2046, 2045, Bibcode:1990AJ….100.2030Z, doi:10.1086/115658. See p. 2045 and family 44.
- Lightcurve plot of 54 Alexandra, Palmer Divide Observatory, B. D. Warner (2008)
- Asteroid Lightcurve Database (LCDB), query form (info Archived 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
- 54 Alexandra at AstDyS-2, Asteroids—Dynamic Site
- 54 Alexandra at the JPL Small-Body Database
