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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.


Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 47 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .220028717149572 1.667e-08  
a 2.689083394035981 7.7127e-09 au
q 2.097407824538027 4.4129e-08 au
i 7.838266638321725 7.622e-07 deg
node 154.8761964074202 6.4867e-06 deg
peri 107.1218631680469 7.6053e-06 deg
M 135.0646558834719 5.3593e-06 deg
tp 2458596.211890553430
(2019-Apr-22.71189055)
2.2782e-05 TDB
period 1610.663559447061
4.41
6.9295e-06
1.897e-08
d
yr
n .2235103649601333 9.6159e-10 deg/d
Q 3.280758963533935 9.4097e-09 au
  Orbit Determination Parameters
   # obs. used (total)      3151  
   data-arc span      37935 days (103.86 yr)  
   first obs. used      1917-05-10  
   last obs. used      2021-03-20  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .40964  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-May-03 18:57:45  

Additional Information
 Earth MOID = 1.09652 au 
 Jupiter MOID = 1.86792 au 
 T_jup = 3.324 
[ hide covariance matrix ]
Orbital Elements at Epoch 2457101.5 (2015-Mar-20.0) TDB
Reference: JPL 47 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2195511615300006 1.6612e-08  
q 2.09937674264694 4.3931e-08 au
tp 2456986.125028116379
(2014-Nov-24.62502812)
2.1084e-05 TDB
node 154.9226856642649 6.4879e-06 deg
peri 107.2834953802244 7.616e-06 deg
i 7.837283120315779 7.6265e-07 deg
  Orbit Determination Parameters
   # obs. used (total)      3151  
   data-arc span      37935 days (103.86 yr)  
   first obs. used      1917-05-10  
   last obs. used      2021-03-20  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .40964  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-May-03 18:57:45  

Additional Information
 Jupiter MOID = 1.86792 au 
 T_jup = 3.324 
Orbit Covariance (6×6)
  e q tp node peri i
e 2.759467244230888E-16 -7.230353036608138E-16 -8.389411352253984E-14 -4.290874209520116E-14 -1.327284016688654E-15 -4.978613232890873E-15
q -7.230353036608138E-16 1.929904012149751E-15 2.390601819631081E-13 1.152419598256743E-13 6.388920553667365E-15 1.336313049287575E-14
tp -8.389411352253984E-14 2.390601819631081E-13 4.445226509873126E-10 2.077011136227464E-11 9.15337611005295E-11 1.697703266342504E-12
node -4.290874209520116E-14 1.152419598256743E-13 2.077011136227464E-11 4.209306343811204E-11 -3.445248171794322E-11 4.676399825935513E-12
peri -1.327284016688654E-15 6.388920553667365E-15 9.15337611005295E-11 -3.445248171794322E-11 5.800359218317983E-11 -3.954644565328273E-12
i -4.978613232890873E-15 1.336313049287575E-14 1.697703266342504E-12 4.676399825935513E-12 -3.954644565328273E-12 5.816388124780789E-13

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 11.97   n/a MPCxxxxx  
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. 2020-October); 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.]
[Franco, L.; Marchini, A.; Arena, C.; Casalnuovo, G.B.; et al. (2020) Minor Planet Bull. 47, 61-63.]
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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