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624 Hektor (1907 XM)
Classification: Jupiter Trojan          SPK-ID: 2000624
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]

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Orbit Diagram
Note: Make sure you have Java enabled on your browser to see the applet. This applet is provided as a 3D orbit visualization tool. The applet was implemented using 2-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances. For accurate long-term ephemerides, please instead use our Horizons system.

Note: If the applet has stopped working because of a recent Java upgrade, here is a possible workaround.
Orbit Viewer

Additional Notes: the orbits shown in the applet are color coded. The planets are white lines, and the asteroid/comet is a blue line. The bright white line indicates the portion of the orbit that is above the ecliptic plane, and the darker portion is below the ecliptic plane. Likewise for the asteroid/comet orbit, the light blue indicates the portion above the ecliptic plane, and the dark blue the portion below the ecliptic plane.

Orbit Viewer applet originally written and kindly provided by Osamu Ajiki (AstroArts), and further modified by Ron Baalke (JPL).

Orbital Elements at Epoch 2457400.5 (2016-Jan-13.0) TDB
Reference: JPL 82 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .02444698181769273 4.4901e-08  
a 5.252597062432108 6.3295e-08 au
q 5.124186917551164 2.5664e-07 au
i 18.16691020216623 5.1328e-06 deg
node 342.7963417748175 1.5693e-05 deg
peri 183.5753739922011 0.0001035 deg
M 72.22809865978552 0.0001016 deg
tp 2456518.307749656259
0.0012402 JED
period 4397.031294146071
n .08187342229728527 1.4799e-09 deg/d
Q 5.381007207313051 6.4842e-08 au
  Orbit Determination Parameters
   # obs. used (total)      1557  
   data-arc span      39604 days (108.43 yr)  
   first obs. used      1907-02-11  
   last obs. used      2015-07-18  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-BIG16  
   condition code      0  
   fit RMS      .54323  
   data source      ORB  
   producer      Otto Matic  
   solution date      2015-Oct-05 13:05:50  

Additional Information
 Earth MOID = 4.13186 au 
 Jupiter MOID = .27999 au 
 T_jup = 2.899 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 7.3 mag n/a MPO347517  
diameter diameter 225 km n/a J.G. Williams 9-90  
rotation period rot_per 6.924 h n/a LCDB (Rev. 2015-December); Warner et al., 2009 Published Reference List:
[Dunlap, J.L.; Gehrels, T. (1969) Astron. J. 74, 796-803.]
[Magnusson, P. (1983) in Asteroids, Comets, Meteors. C.-I. Lagerkvist, H. Rickman, eds. Uppsala, pp. 77-85.]
[Magnusson, P. (1986) Icarus 68, 1-39.]
[Uchida, K.; Goguen, J.D. (1987) Bull. Amer. Astron. Soc. 19, 842.]
[Michalowski, T. (1988) Acta Astronomica 38, 455-468.]
[De Angelis, G. (1992) in Physical properties of small solar system bodies. A. Brahic, J.-C. Gerard, J. Surdej, eds. Universite de Liege, Institut d'Astrophysique, Liege, pp. 195-201.]
[De Angelis, G. (1995) Planet. Space Sci. 43, 649-682.]
[Szabo, Gy.; Sarneczky, K.; Kiss, L.L. (1999) in Proc. IAU Coll. 173, Evolution and Source Regions of Asteroids and Comets, 185-188.]
[Kaasalainen, M.; Torppa, J.; Piironen, J. (2002) Astron. Astrophys. 383, L19-L22.]
[Hamanowa, H.; Hamanowa, H. (2009) Minor Planet Bul. 36, 87-88.]
[Stephens, R.D. (2009) Minor Planet Bul. 36, 59-62.]
[Behrend, R. (2009) Observatoire de Geneve web site,]
[Behrend, R. (2010) Observatoire de Geneve web site,]
[Behrend, R. (2013) Observatoire de Geneve web site,]
[Marchis, F.; Durech, J.; Castillo-Rogez, J.; Vachier, F.; et al. (2014). Astrophys. J. Letters 783, L37.]
[Stephens, R.D.; Coley, D.R.; French, L.M. (2014) Minor Planet Bul. 41, 210-212.]
[Hanus, J.; Delbo, M.; Durech, J.; Ali-Lagoa, V. (2015) Icarus 256, 101-116.]
geometric albedo albedo 0.025   n/a EAR-A-5-DDR-ALBEDOS-V1.0:TRIAD TRIAD quality code 3
B-V BV .776 mag .027 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.1 #obs=9; phase (min.=3.84, mean=5.77, max.=7.78) deg.
U-B UB .249 mag .034 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.1 #obs=7; phase (min.=3.84, mean=6.11, max.=7.78) deg.
Tholen spectral type spec_T D   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo

624 Hektor (1907 XM)          Discovered 1907-Feb-10 by Kopff, A. at Heidelberg
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 1907 XM = 1948 VD 
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]
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