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JPL Small-Body Database Browser
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85 Io
Classification: Main-belt Asteroid          SPK-ID: 2000085
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 100 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1947093358323981 3.0324e-08  
a 2.652997727496426 4.2704e-09 au
q 2.136434302010735 8.1026e-08 au
i 11.95939775097892 3.1881e-06 deg
node 203.1041713283868 1.6258e-05 deg
peri 122.9016221142876 1.8001e-05 deg
M 312.1195459044551 9.0382e-06 deg
tp 2459210.422748370008
(2020-Dec-26.92274837)
3.9819e-05 TDB
period 1578.351559958043
4.32
3.8109e-06
1.043e-08
d
yr
n .2280860672191243 5.5071e-10 deg/d
Q 3.169561152982117 5.1019e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2714  
   data-arc span      56353 days (154.29 yr)  
   first obs. used      1865-09-21  
   last obs. used      2020-01-05  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .47634  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Jan-28 17:14:34  

Additional Information
 Earth MOID = 1.15288 au 
 Jupiter MOID = 2.33524 au 
 T_jup = 3.332 
[ 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 7.7   n/a MPO473761 IRAS observations used: 8
diameter diameter 154.79 km 3.8 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 8
rotation period rot_per 6.875 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List:
[Yang, X.-y.; Zhang, Y.-y.; Li, X.-q. (1965) Acta Astron. Sin. 13, 66-74.]
[Lagerkvist, C.-I.; Schober, H.J. (1981) Astron. Astrophys. Suppl. Ser. 44, 401-404.]
[Erikson, A.; Berthier, J.; Denchev, P.V.; Harris, A.W.; et al. (1999) Planet. Space Sci. 47, 327-330.]
[Torppa, J.; Kaasalainen, M.; Michalowski, T.; Kwiatkowski, T.; et al. (2003) Icarus 164, 346-383.]
[Behrend, R. (2005) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Behrend, R. (2006) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Behrend, R. (2011) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Durech, J.; Kaasalainen, M.; Herald, D.; Dunham, D.; et al. (2011) Icarus 214, 652-670.]
[Hanus, J.; Marchis, F.; Durech, J. (2013) Icarus 226, 1045-1057.]
[Behrend, R. (2016) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Hanus, J.; Viikinkoski, M.; Marchis, F.; Durech, J.; et al (2017) Astron. Astrophys. 601, A114.]
geometric albedo albedo 0.0666   0.003 IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 8
B-V BV 0.668   0.023 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=8; phase (min.=6.05, mean=11.20, max.=19.29) deg.
U-B UB 0.294   0.015 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=7; phase (min.=6.05, mean=10.95, max.=19.29) deg.
Tholen spectral type spec_T FC   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo
SMASSII spectral type spec_B B   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)

85 Io          Discovered 1865-Sep-19 by Peters, C. H. F. at Clinton
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 A899 LA = A899 UA 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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