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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 14 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .02313842502530853 6.5339e-08  
a 5.080290210488324 1.4531e-07 AU
q 4.962740296346132 3.6664e-07 AU
i 2.328975268548039 7.3662e-06 deg
node 52.29127458648249 0.00018656 deg
peri 39.75016556529501 0.00030903 deg
M 84.03270421093414 0.00023827 deg
tp 2456024.214029050618
(2012-Apr-06.71402905)
0.0027826 JED
period 4182.454353242699
11.45
0.00017944
4.913e-07
d
yr
n .08607386228157837 3.6929e-09 deg/d
Q 5.197840124630518 1.4867e-07 AU
  Orbit Determination Parameters
   # obs. used (total)      779  
   data-arc span      15045 days (41.19 yr)  
   first obs. used      1973-09-19  
   last obs. used      2014-11-28  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-BIG16  
   condition code      0  
   fit RMS      .52281  
   data source      ORB  
   producer      Otto Matic  
   solution date      2015-Jan-08 02:48:26  

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 11.9 mag n/a MPO263534  

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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