624 Hektor

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624 Hektor
624Hektor-LB1-mag15.jpg
Star field showing Hektor (apmag 15)
Discovery
Discovered by August Kopff
Discovery date 10 February 1907
Designations
Named after Hector
Alternate name(s) 1907 XM; 1948 VD
Minor planet
category
Trojan asteroid
Adjective Hektorian
Epoch 22 October 2004 (JD 2453300.5)
Aphelion 5.349 AU (800.220 Gm)
Perihelion 5.095 AU (762.145 Gm)
Semi-major axis 5.222 AU (781.183 Gm)
Eccentricity 0.024
Orbital period 11.93 a (4358.521 d)
Average orbital speed 13.03 km/s
Mean anomaly 94.752°
Inclination 18.198°
Longitude of ascending node 342.791°
Argument of perihelion 183.579°
Satellites S/2006 (624) 1[2]
(15km diameter)
Physical characteristics
Dimensions 370 km × 195 km × 195 km[3]
Mass ~1.4×1019 kg
Mean density 2 ? g/cm³
Equatorial surface gravity ~0.067 m/s²
Escape velocity ~0.13 km/s
Rotation period 0.2884 d (6.92 h)[4]
Albedo 0.025 (geometric)[1]
Temperature ~122 K
Spectral type D
Apparent magnitude 13.79 to 15.26
Absolute magnitude (H) 7.49[1]
Angular diameter 0.078" to 0.048"

624 Hektor (play /ˈhɛktɔr/ hek-tor) 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 being 617 Patroclus in the Trojan node).

Contents

[edit] Contact binary plus moonlet

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[citation needed] because of a limited angular resolution. On 17 July 2006, the Keck-10m II telescope and its Laser guide star Adaptive Optics (AO) system indicated a bilobate shape for Hektor[citation needed]. Additionally, a 15-km moonlet at 1000 km of Hektor was detected. The satellite's provisional designation is S/2006 (624) 1.[2] Hektor is, so far, the only known binary trojan asteroid in the L4 point and the first trojan with a satellite companion. 617 Patroclus, another large trojan asteroid located in the L5, is composed of two same-sized components.

[edit] Hektor in fiction

See Asteroids in fiction.

[edit] References

  1. ^ a b c "JPL Small-Body Database Browser: 624 Hektor (1907 XM)". 5 September 2008 last obs. http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=624. Retrieved 1 November 2008. 
  2. ^ a b "IAUC 8732: S/2006 (624) 1 (Satellite Discovery)". http://cfa-www.harvard.edu/iauc/08700/08732.html#Item1. Retrieved 23 July 2006. 
  3. ^ Storrs, Alex; Weiss, B.; Zellner, B. et al (1998). "Imaging Observations of Asteroids with Hubble Space Telescope". Icarus 137 (2): 260–268. Bibcode 1999Icar..137..260S. doi:10.1006/icar.1999.6047. http://web.media.mit.edu/~win/hstpub.pdf. Retrieved 22 May 2008. 
  4. ^ Detal, A.; Hainaut, O.; Pospieszalska-Surdej, A.; Schils, P.; Schober, H. J.; Surdej, J. (1994). "Pole, albedo and shape of the minor planets 624 Hektor and 43 Ariadne". Astronomy and Astrophysics (ISSN 0004-6361) 281: 269. Bibcode 1994A&A...281..269D. 

[edit] External links

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