624 Hektor

From Infogalactic: the planetary knowledge core
Jump to: navigation, search
624 Hektor
624Hektor-LB1-mag15.jpg
Star field showing Hektor (apmag 15)
Discovery
Discovered by August Kopff
Discovery date 10 February 1907
Designations
Pronunciation /ˈhɛktɔːr/ HEK-tor
Named after
Hector
1907 XM; 1948 VD
Jupiter trojan (leading cloud)
Adjectives Hektorian
Orbital characteristics[2]
Epoch 22 October 2004 (JD 2453300.5)
Aphelion 5.349 AU (800.220 Gm)
Perihelion 5.095 AU (762.145 Gm)
5.222 AU (781.183 Gm)
Eccentricity 0.024
11.93 a (4358.521 d)
13.03 km/s
94.752°
Inclination 18.198°
342.791°
183.579°
Known satellites S/2006 (624) 1[1]
(diameter of 15 km)
Physical characteristics
Dimensions 370 × 195 × 195 km[3]
226.68 ± 15.15 km[4]
Mass (9.95 ± 0.12) × 1018 kg[4]
Mean density
1.0 ± 0.3 g/cm3[5]
1.63 ± 0.32 g/cm3[4]
2.43 ± 0.35 g/cm3[6]
~ 0.067 m/s²
~ 0.13 km/s
0.2884 d (6.92 h)[7]
Albedo 0.025 (geometric)[2]
Temperature ~ 122 K
Spectral type
D
13.79 to 15.26
7.49[2]
0.078" to 0.048"

624 Hektor is the largest Jupiter trojan. It was discovered in 1907 by August Kopff.

Hektor is a D-type asteroid, dark and reddish in colour. It lies in Jupiter's leading Lagrangian point, L4, called the 'Greek' node after one of the two sides in the legendary Trojan War. Hektor is named after the Trojan hero Hektor and is thus one of two trojan asteroids that is "misplaced" in the wrong camp (the other one being 617 Patroclus in the Trojan node).

Contact binary plus moon

Hektor is one of the most elongated bodies of its size in the Solar System, being 370 × 200 km. It is thought that Hektor might be a contact binary (two asteroids joined by gravitational attraction) like 216 Kleopatra. Hubble Space Telescope observations of Hektor in 1993 did not show an obvious bilobate shape because of a limited angular resolution. On 17 July 2006, the Keck 10-meter-II-telescope and its laser guide star adaptive optics (AO) system indicated a bilobate shape for Hektor.[8] Additionally, a 12-km-diameter moon of Hektor, S/2006 (624) 1, was detected orbiting with a semi-major axis of 623.5 km and an orbital period of 2.9651 day.[1][5] It was confirmed with Keck observations in November 2011.[9] Hektor is, so far, the only known binary trojan asteroid in the L4 point and the first known trojan with a satellite companion. 617 Patroclus, another large trojan asteroid located in the L5, is composed of two same-sized components.[8]

The largest Jupiter trojans
Trojan Diameter (km)
624 Hektor 225
911 Agamemnon 167
1437 Diomedes 164
1172 Äneas 143
617 Patroclus 141
588 Achilles 135
1173 Anchises 126
1143 Odysseus 126
Source: JPL Small-Body Database, IRAS data

Hektor in fiction

References

  1. 1.0 1.1 "IAUC 8732: S/2006 (624) 1 (Satellite Discovery)". Retrieved 23 July 2006.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  2. 2.0 2.1 2.2 "JPL Small-Body Database Browser: 624 Hektor (1907 XM)" (5 September 2008 last obs). Retrieved 1 November 2008.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  3. Lua error in Module:Citation/CS1/Identifiers at line 47: attempt to index field 'wikibase' (a nil value).
  4. 4.0 4.1 4.2 Lua error in Module:Citation/CS1/Identifiers at line 47: attempt to index field 'wikibase' (a nil value). See Table 1.
  5. 5.0 5.1 Lua error in Module:Citation/CS1/Identifiers at line 47: attempt to index field 'wikibase' (a nil value).
  6. Lua error in Module:Citation/CS1/Identifiers at line 47: attempt to index field 'wikibase' (a nil value).
  7. Lua error in Module:Citation/CS1/Identifiers at line 47: attempt to index field 'wikibase' (a nil value).
  8. 8.0 8.1 Franck Marchis. "Searching and Characterizing Multiple Trojan Asteroids with LGS AO Systems" (PDF).<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  9. "Tiny moon of (624) Hektor observed with Keck-AO NGS".<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>

External links