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426 Hippo (A897 RA)
Classification: Main-belt Asteroid          SPK-ID: 2000426
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 2458600.5 (2019-Apr-27.0) TDB
Reference: JPL 98 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1048194389669572 4.8605e-08  
a 2.890206276517585 1.2408e-08 au
q 2.587256476114233 1.3865e-07 au
i 19.48541439233107 5.1078e-06 deg
node 311.3337585706271 1.3839e-05 deg
peri 222.5555635222252 2.4849e-05 deg
M 88.18564886054494 2.0852e-05 deg
tp 2458160.870222771082
(2018-Feb-11.37022277)
0.0001039 TDB
period 1794.699271904098
4.91
1.1557e-05
3.164e-08
d
yr
n .2005907093382032 1.2918e-09 deg/d
Q 3.193156076920936 1.3709e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2237  
   data-arc span      42338 days (115.92 yr)  
   first obs. used      1903-12-01  
   last obs. used      2019-10-31  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .4297  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-Nov-07 01:53:20  

Additional Information
 Earth MOID = 1.6248 au 
 Jupiter MOID = 1.92198 au 
 T_jup = 3.198 
[ hide covariance matrix ]
Orbital Elements at Epoch 2455663.5 (2011-Apr-12.0) TDB
Reference: JPL 98 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1028055458111584 4.8854e-08  
q 2.595206932955378 1.3851e-07 au
tp 2456360.660178815323
(2013-Mar-09.16017882)
0.00010611 TDB
node 311.547254942514 1.3837e-05 deg
peri 220.9634942722729 2.5096e-05 deg
i 19.47148876675798 5.109e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      2237  
   data-arc span      42338 days (115.92 yr)  
   first obs. used      1903-12-01  
   last obs. used      2019-10-31  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .4297  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-Nov-07 01:53:20  

Additional Information
 Jupiter MOID = 1.92198 au 
 T_jup = 3.198 
Orbit Covariance (6×6)
  e q tp node peri i
e 2.386682118345548E-15 -6.746597290255552E-15 -3.391412212070438E-13 3.581613742726158E-15 -6.710610463372652E-14 -5.028410966081458E-17
q -6.746597290255552E-15 1.918532127286878E-14 8.920602935426597E-13 -1.116976022688094E-14 1.653607346560522E-13 -1.738764254744928E-15
tp -3.391412212070438E-13 8.920602935426597E-13 1.126027819247714E-8 1.089522157099208E-11 2.246866242553008E-9 6.459418927555817E-12
node 3.581613742726158E-15 -1.116976022688094E-14 1.089522157099208E-11 1.91471767546447E-10 -1.776587951833816E-10 1.334779197490394E-11
peri -6.710610463372652E-14 1.653607346560522E-13 2.246866242553008E-9 -1.776587951833816E-10 6.298008172337113E-10 -1.100331995406243E-11
i -5.028410966081458E-17 -1.738764254744928E-15 6.459418927555817E-12 1.334779197490394E-11 -1.100331995406243E-11 2.610162702986202E-11

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 8.42   n/a IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 14
diameter diameter 137.562 km 1.081 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  
rotation period rot_per 34.3 h n/a LCDB (Rev. 2019-January); 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:
[Pray, D.P. (2006) Minor Planet Bull. 33, 4-5.]
geometric albedo albedo 0.040   0.009 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  
B-V BV 0.710   0.025 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=1; phase=10.49 deg.
U-B UB 0.345   0.037 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=1; phase=10.49 deg.
Tholen spectral type spec_T F   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 2 color indices

426 Hippo (A897 RA)          Discovered 1897-Aug-25 by Charlois, A. at Nice
Reference: DISCOVERY.DBLast Updated: 2003-08-29

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