Astronomy:858 El Djezaïr
| Discovery [1] | |
|---|---|
| Discovered by | F. Sy |
| Discovery site | Algiers Observatory |
| Discovery date | 26 May 1916 |
| Designations | |
| (858) El Djezaïr | |
| Pronunciation | /ɛlˌdʒɛzɑːˈɪər/ |
| Named after | Algiers (Arabic name)[2] |
| 1916 a · A908 UC A911 HE | |
| Minor planet category | main-belt |
| Orbital characteristics [1] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 106.80 yr (39010 days) |
| |{{{apsis}}}|helion}} | 3.0983 astronomical unit|AU (463.50 Gm) |
| |{{{apsis}}}|helion}} | 2.5252 AU (377.76 Gm) |
| 2.8118 AU (420.64 Gm) | |
| Eccentricity | 0.10192 |
| Orbital period | 4.71 yr (1722.1 d) |
| Mean anomaly | 102.29° |
| Mean motion | 0° 12m 32.544s / day |
| Inclination | 8.8726° |
| Longitude of ascending node | 67.197° |
| 179.05° | |
| Earth MOID | 1.51148 AU (226.114 Gm) |
| Jupiter MOID | 1.9171 AU (286.79 Gm) |
| TJupiter | 3.296 |
| Physical characteristics | |
| Mean radius | 11.755±1.3 km |
| Rotation period | 22.31 h (0.930 d) |
| Geometric albedo | 0.3197±0.085 |
| Tholen = S | |
| Absolute magnitude (H) | 10.2 |
858 El Djezaïr /ɛlˌdʒɛzɑːˈɪər/ is a stony asteroid from the asteroid belt, about 24 kilometers in diameter. It was discovered on May 26, 1916, by French astronomer Frédéric Sy at the Algiers Observatory in Algeria, North Africa, and given the provisional designation 1916 a.[1]
The asteroid orbits the Sun at a distance of 2.5–3.1 AU once every 4.71 years (1,722 days). The bright S-type asteroid has a very high geometric albedo of 0.32. Its rotation period has been measured to take 22 hours and 20 minutes.[3] Along with the asteroids 68 Leto and 236 Honoria, it is a member of the Leto family, a small, well-defined group of asteroids, all with a semi-major axis of close to 2.8 AU.
El Djezaïr is the French spelling of the Arabic name for Algiers, the capital of Algeria. It means "the islands". The asteroid was the first minor planet to receive a name that consists of more than one word.[2] Its designation, 1916 a, is a superseded version of the modern two-letter code system of provisional designation, implemented just a few years later in 1925.
References
- ↑ 1.0 1.1 1.2 "JPL Small-Body Database Browser: 858 El Djezair (1916 a)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2000858.
- ↑ 2.0 2.1 Schmadel, Lutz D. (2003). "(858) el Djezaïr". Dictionary of Minor Planet Names – (858) El Djezaïr. Springer Berlin Heidelberg. p. 78. doi:10.1007/978-3-540-29925-7_859. ISBN 978-3-540-29925-7.
- ↑ Behrend, R. (December 2007). "Asteroids and comets rotation curves—(858) El Djezair, E=2007-12-01". Geneva Observatory. http://obswww.unige.ch/~behrend/page3cou.html#000858.
External links
- Lightcurve plot of 858 El Djezair, Palmer Divide Observatory, B. D. Warner (2005)
- Asteroid Lightcurve Database (LCDB), query form (info )
- 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
- 858 El Djezaïr at AstDyS-2, Asteroids—Dynamic Site
- 858 El Djezaïr at the JPL Small-Body Database
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