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20947 Polyneikes (2638 T-2)
Classification: Jupiter Trojan          SPK-ID: 2020947
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2457400.5 (2016-Jan-13.0) TDB
Reference: JPL 17 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .0226761774212672 6.2499e-08  
a 5.076656947454523 1.242e-07 au
q 4.961537773807136 3.2027e-07 au
i 2.329407508542228 6.8837e-06 deg
node 52.28263081655795 0.00017371 deg
peri 37.70744788944908 0.0002816 deg
M 120.6069445510837 0.00021593 deg
tp 2456000.799985629745
(2012-Mar-14.29998563)
0.0025133 JED
period 4177.968416734622
11.44
0.00015332
4.198e-07
d
yr
n .08616628085507774 3.1621e-09 deg/d
Q 5.19177612110191 1.2702e-07 au
  Orbit Determination Parameters
   # obs. used (total)      857  
   data-arc span      15210 days (41.64 yr)  
   first obs. used      1973-09-19  
   last obs. used      2015-05-12  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-BIG16  
   condition code      0  
   fit RMS      .52703  
   data source      ORB  
   producer      Otto Matic  
   solution date      2015-Jun-04 16:38:16  

Additional Information
 Earth MOID = 3.9779 au 
 Jupiter MOID = .0578515 au 
 T_jup = 2.998 
[ 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 12.0 mag n/a MPO337435  

20947 Polyneikes           Discovered 1973 Sept. 29 by C. J. van Houten and I. van Houten-Groeneveld on Palomar Schmidt plates taken by T. Gehrels.
Polyneikes was the father of Thersander, son of Oedipus and friend of Diomedes' father Tydeus. Polyneikes is a main character in The Seven against Thebes. He fought against his own brother.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20010309/MPCPages.arcLast Updated: 2009-05-11

Alternate Designations
 2638 T-2 = 1998 SP145 
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]
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