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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 2457000.5 (2014-Dec-09.0) TDB
Reference: JPL 17 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .02313842460953455 6.1561e-08  
a 5.080290209030498 1.2598e-07 AU
q 4.96274029703429 3.1831e-07 AU
i 2.32897752672556 6.8808e-06 deg
node 52.29133639725087 0.00017375 deg
peri 39.75010695412661 0.00027899 deg
M 84.03270126573685 0.00021276 deg
tp 2456024.214063687939
(2012-Apr-06.71406369)
0.0024773 JED
period 4182.45435144242
11.45
0.00015557
4.259e-07
d
yr
n .08607386231862764 3.2017e-09 deg/d
Q 5.197840121026707 1.289e-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 = 3.97947 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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