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2920 Automedon (1981 JR)
Classification: Jupiter Trojan          SPK-ID: 2002920
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 39 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .02698405535655873 4.9794e-08  
a 5.109183706955363 7.2069e-08 au
q 4.971317210980051 2.9803e-07 au
i 21.11984217046957 4.3184e-06 deg
node 230.942140243926 1.2742e-05 deg
peri 196.7385991782068 9.3212e-05 deg
M 290.3916942401518 9.4001e-05 deg
tp 2459816.113240206933
(2022-Aug-24.61324021)
0.0011046 TDB
period 4218.185793624983
11.55
8.9251e-05
2.444e-07
d
yr
n .08534474715269161 1.8058e-09 deg/d
Q 5.247050202930674 7.4014e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2791  
   data-arc span      14442 days (39.54 yr)  
   first obs. used      1981-05-03  
   last obs. used      2020-11-16  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .404  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Dec-18 02:09:06  

Additional Information
 Earth MOID = 3.98657 au 
 Jupiter MOID = .0354407 au 
 T_jup = 2.866 
[ hide covariance matrix ]
Orbital Elements at Epoch 2457349.5 (2015-Nov-23.0) TDB
Reference: JPL 39 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .02615675229071151 4.9329e-08  
q 4.974295969982121 2.9648e-07 au
tp 2455631.765037911318
(2011-Mar-11.26503791)
0.0011437 TDB
node 230.950947896067 1.2739e-05 deg
peri 199.3209877487812 9.7633e-05 deg
i 21.12434660525248 4.3193e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      2791  
   data-arc span      14442 days (39.54 yr)  
   first obs. used      1981-05-03  
   last obs. used      2020-11-16  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .404  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Dec-18 02:09:06  

Additional Information
 Jupiter MOID = .0354407 au 
 T_jup = 2.866 
Orbit Covariance (6×6)
  e q tp node peri i
e 2.433357959611272E-15 -1.43268027504859E-14 -1.618584078020578E-11 -8.175560634729203E-15 -1.345957505730234E-12 -2.250708528232491E-15
q -1.43268027504859E-14 8.789839615577953E-14 9.261702251308153E-11 5.581698029569404E-14 7.850340382568817E-12 1.711700641164142E-14
tp -1.618584078020578E-11 9.261702251308153E-11 1.307970080839778E-6 1.089598681293907E-10 1.107336434399236E-7 1.006422002646534E-10
node -8.175560634729203E-15 5.581698029569404E-14 1.089598681293907E-10 1.622869986628364E-10 -1.415086900308927E-10 -1.164344423622518E-11
peri -1.345957505730234E-12 7.850340382568817E-12 1.107336434399236E-7 -1.415086900308927E-10 9.532122073391241E-9 1.959206206208533E-11
i -2.250708528232491E-15 1.711700641164142E-14 1.006422002646534E-10 -1.164344423622518E-11 1.959206206208533E-11 1.865658758002961E-11

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

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 8.7   n/a MPO502181  
diameter diameter 88.574 km 1.796 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)  
rotation period rot_per 10.212 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List:
[Molnar, L.A.; Haegert, M.J.; Hoogenboom, K.M. (2008) Minor Planet Bull. 35, 82-84.]
[Mottola, S.; Di Martino, M.; Erikson, A.; Gonano-Beurer, M.; et al. (2011) Astron. J. 141, A170.]
[Stephens, R.D. Warner, B.D. (2017) Minor Planet Bull. 44, 312-316.]
[Stephens, R.D.; Warner, B.D. (2019) Minor Planet Bull. 46, 73-75.]
[Stephens, R.D.; Warner, B.D. (2020) Minor Planet Bull. 47, 43-46.]
geometric albedo albedo 0.068   0.009 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)  

2920 Automedon (1981 JR)          Discovered 1981-May-03 by Bowell, E. at Flagstaff (AM)
Discovered at the Anderson Mesa station, which is operated by the Lowell Observatory.
Reference: DISCOVERY.DBLast Updated: 2003-08-29
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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