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869 Mellena (A917 JB)
Classification: Main-belt Asteroid          SPK-ID: 2000869
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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For accurate long-term ephemerides, please instead use our Horizons system.This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.


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Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 39 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2201975279039724 3.2825e-08  
a 2.688675807326792 8.4891e-09 au
q 2.096636041218215 8.8483e-08 au
i 7.838534931288519 4.6161e-06 deg
node 154.8793588821873 2.7517e-05 deg
peri 107.0904982727644 2.9348e-05 deg
M 90.37593018000599 1.03e-05 deg
tp 2458596.244101454915
(2019-Apr-22.74410145)
4.5629e-05 TDB
period 1610.297378808355
4.41
7.6264e-06
2.088e-08
d
yr
n .223561191080374 1.0588e-09 deg/d
Q 3.280715573435368 1.0358e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2566  
   data-arc span      37707 days (103.24 yr)  
   first obs. used      1917-05-10  
   last obs. used      2020-08-04  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .43871  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Aug-24 22:23:51  

Additional Information
 Earth MOID = 1.09745 au 
 Jupiter MOID = 1.86884 au 
 T_jup = 3.325 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 11.9   n/a MPO448919  
diameter diameter 21.193 km 0.090 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  
rotation period rot_per 6.5155 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List:
[Stephens, R.D. (2010) Minor Planet Bull. 37, 159-161.]
[Carbognani, A. (2011) Minor Planet Bull. 38, 57-63.]
[Ferrero, A. (2011) Entry on CALL web site. http://www.minorplanet.info/call.html]
[Owings, L.E. (2011) Minor Planet Bull. 38, 9-10.]
geometric albedo albedo 0.065   0.009 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  

869 Mellena (A917 JB)          Discovered 1917-May-09 by Schorr, R. at Bergedorf
Independent discovery May 10 by M. Wolf, Heidelberg, was announced first.
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 A917 JB = 1931 RC = 1944 OB = 1952 DL2 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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