Skip Page Navigation
NASA JPL Caltech
NASA Logo - Jet Propulsion Laboratory + View the NASA Portal
+ Center for Near-Earth Object Studies
JPL Home Earth Solar System Stars & Galaxies Technology
JPL Solar System Dynamics
JPL Small-Body Database Browser
Search: [ help ]  
624 Hektor (A907 CF)
Classification: Jupiter Trojan          SPK-ID: 2000624
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ hide orbit diagram ]

For accurate long-term ephemerides, please instead use our Horizons system.This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.

Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 106 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .02262934361434583 2.18e-08  
a 5.263860462319051 5.0526e-08 au
q 5.144742755179263 1.0947e-07 au
i 18.15609763764343 3.8641e-07 deg
node 342.7878018796097 2.1549e-06 deg
peri 183.4362002247521 4.5909e-05 deg
M 219.6678471728509 4.5366e-05 deg
tp 2460920.029639568062
0.00056818 TDB
period 4411.182026167437
n .08161077866758956 1.175e-09 deg/d
Q 5.382978169458839 5.1669e-08 au
  Orbit Determination Parameters
   # obs. used (total)      3857  
   data-arc span      41650 days (114.03 yr)  
   first obs. used      1907-02-11  
   last obs. used      2021-02-22  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .33522  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Apr-12 11:11:44  

Additional Information
 Earth MOID = 4.15205 au 
 Jupiter MOID = .27088 au 
 T_jup = 2.899 
[ show covariance matrix ]

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

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 7.32   n/a MPCxxxxx  
diameter diameter 225 km n/a J.G. Williams 9-90  
rotation period rot_per 6.924 h n/a LCDB (Rev. 2020-October); 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.]
[Lacerda, P.; Jewitt, D.C. (2007) Astron. J. 133, 1393-1408.]
[Behrend, R. (2009) Observatoire de Geneve web site,]
[Hamanowa, H.; Hamanowa, H. (2009) Minor Planet Bull. 36, 87-88.]
[Stephens, R.D. (2009) Minor Planet Bull. 36, 59-62.]
[Behrend, R. (2010) Observatoire de Geneve web site,]
[Behrend, R. (2013) Observatoire de Geneve web site,]
[Gorshanov, D.L.; Arkharov, A.A.; Larionov, V.M. (2014) Solar System Research 48, 202-211.]
[Marchis, F.; Durech, J.; Castillo-Rogez, J.; Vachier, F.; et al. (2014). Astrophys. J. Let. 783, L37.]
[Stephens, R.D.; Coley, D.R.; French, L.M. (2014) Minor Planet Bull. 41, 210-212.]
[Hanus, J.; Delbo, M.; Durech, J.; Ali-Lagoa, V. (2015) Icarus 256, 101-116.]
[Behrend, R. (2020) Observatoire de Geneve web site,]
[Pal, A.; Szakats, R.; Kiss, C.; Bodi, A.; et al. (2019) Ap. J. Supl. Ser. 247, id.26.]
[Stephens, R.D.; Warner, B.D. (2020) Minor Planet Bull. 47, 43-46.]
geometric albedo albedo 0.025   n/a EAR-A-5-DDR-ALBEDOS-V1.0:TRIAD TRIAD quality code 3
B-V BV 0.776   0.027 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=9; phase (min.=3.84, mean=5.77, max.=7.78) deg.
U-B UB 0.249   0.034 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #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 (A907 CF)          Discovered 1907-Feb-10 by Kopff, A. at Heidelberg
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 A907 CF = 1948 VD 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
FirstGov 2021-Jun-19 02:46 UT
(server date/time)  
NASA Home Page
Site Manager:   Ryan S. Park
Webmaster  Alan B. Chamberlin