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498 Tokio (A902 XA)
Classification: Main-belt Asteroid          SPK-ID: 2000498
[ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

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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 84 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2229031376686673 2.2447e-08  
a 2.651965104945906 6.5767e-09 au
q 2.060833762065647 5.7967e-08 au
i 9.496432726635184 5.8613e-07 deg
node 97.20851095999754 2.8896e-06 deg
peri 241.8007592040371 3.3062e-06 deg
M 183.0888623214838 3.6589e-06 deg
tp 2459975.680446477733
(2023-Jan-31.18044648)		 1.8294e-05 TDB
period 1577.430140317688
4.32		 5.8679e-06
1.607e-08		 d
yr
n .2282192984644615 8.4896e-10 deg/d
Q 3.243096447826165 8.0427e-09 au
   Orbit Determination Parameters
   # obs. used (total)      4559  
   data-arc span      42735 days (117.00 yr)  
   first obs. used      1904-03-14  
   last obs. used      2021-03-15  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .37789  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Apr-12 10:58:50  

Additional Information
 Earth MOID = 1.0693 au 
 Jupiter MOID = 2.19499 au 
 T_jup = 3.335 
[ 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 8.9   n/a MPO502157 IRAS observations used: 15
diameter diameter 81.83 km 2.3 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 15
rotation period rot_per 41.85 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List:
[Pilcher, F.; Martinez, L. (2013) Minor Planet Bull. 40, 196-197.]
[Pal, A.; Szakats, R.; Kiss, C.; Bodi, A.; et al. (2019) Ap. J. Supl. Ser. 247, id.26.]
geometric albedo albedo 0.0694   0.004 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 15
B-V BV 0.780   0.024 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=.73, mean=10.06, max.=21.97) deg.
U-B UB 0.375   0.025 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=.73, mean=10.06, max.=21.97) deg.
Tholen spectral type spec_T M   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo

498 Tokio (A902 XA)          Discovered 1902-Dec-02 by Charlois, A. at Nice
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 A902 XA = A900 EB 
[ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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