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JPL Small-Body Database Browser
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221 Eos
Classification: Main-belt Asteroid          SPK-ID: 2000221
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.


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Orbital Elements at Epoch 2458600.5 (2019-Apr-27.0) TDB
Reference: JPL 35 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1042781750066008 3.9404e-08  
a 3.010967444252915 1.2679e-08 au
q 2.696989254161932 1.2105e-07 au
i 10.87905290836612 4.4383e-06 deg
node 141.8202008739156 2.4774e-05 deg
peri 192.9950611982478 3.4805e-05 deg
M 255.914772641534 2.656e-05 deg
tp 2459152.252247602525
(2020-Oct-29.75224760)
0.00014219 TDB
period 1908.347747109504
5.22
1.2053e-05
3.3e-08
d
yr
n .1886448633616578 1.1915e-09 deg/d
Q 3.324945634343898 1.4001e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2652  
   data-arc span      48869 days (133.80 yr)  
   first obs. used      1885-10-29  
   last obs. used      2019-08-17  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .46261  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-Sep-23 19:06:31  

Additional Information
 Earth MOID = 1.68681 au 
 Jupiter MOID = 2.03053 au 
 T_jup = 3.214 
[ 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 MPO492751 IRAS observations used: 15
magnitude slope G 0.13   n/a PDS3 (MPC 17258) Fit
diameter diameter 95.469 km 1.684 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  
rotation period rot_per 10.443 h n/a LCDB (Rev. 2019-January); Warner et al., 2009 Published Reference List:
[Harris, A.W.; Young, J.W. (1980) Icarus 43, 20-32.]
[Harris, A.W.; Young, J.W. (1983) Icarus 54, 59-109.]
[Behrend, R. (2007) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Pilcher, F. (2013) Minor Planet Bull. 40, 158-160.]
[Behrend, R. (2014) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Hanus, J.; Delbo, M.; Ali-Lagoa, V.; Bolin, B.; et al. (2016) Astron. Astrophys., submitted.]
[Hanus, J.; Delbo, M.; Ali-Lagoa, V.; Bolin, B.; et al. (2018) Icarus 299, 84-96.]
geometric albedo albedo 0.166   0.013 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  
B-V BV 0.768   0.031 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=1.96, mean=8.64, max.=12.71) deg.
U-B UB 0.410   0.062 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=1.96, mean=8.64, max.=12.71) deg.
Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo
SMASSII spectral type spec_B K   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)

221 Eos          Discovered 1882-Jan-18 by Palisa, J. at Vienna
Reference: DISCOVERY.DBLast Updated: 2003-08-29
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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