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39494 (1981 EM11)
Classification: Main-belt Asteroid          SPK-ID: 2039494
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 20 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .0644563196165092 4.543e-08  
a 2.300322800114156 9.4661e-09 au
q 2.152052458488855 1.035e-07 au
i 6.018220368987818 4.9326e-06 deg
node 304.1840789380778 3.6017e-05 deg
peri 173.0374048261575 5.0289e-05 deg
M 140.0643262836338 3.3236e-05 deg
tp 2458504.699867139424
(2019-Jan-21.19986714)
0.0001176 TDB
period 1274.329106958787
3.49
7.866e-06
2.154e-08
d
yr
n .2825015908638762 1.7438e-09 deg/d
Q 2.448593141739457 1.0076e-08 au
  Orbit Determination Parameters
   # obs. used (total)      987  
   data-arc span      13980 days (38.28 yr)  
   first obs. used      1981-02-02  
   last obs. used      2019-05-14  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .5483  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Feb-23 05:28:08  

Additional Information
 Earth MOID = 1.1683 au 
 Jupiter MOID = 2.60024 au 
 T_jup = 3.582 
[ 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 15.5   n/a MPO474252  
rotation period rot_per 7.353 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so.
Published Reference List:
[Waszczak, A.; Chang, C.-K.; Ofeck, E.O.; Laher, F.; et al. (2015) Astron. J. 150, A75.]

39494 (1981 EM11)          Discovered 1981-Mar-07 by Bus, S. J. at Siding Spring
Reference: 20020526/Numbers.arcLast Updated: 2004-04-19
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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