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161 Athor (A876 HA)
Classification: Main-belt Asteroid          SPK-ID: 2000161
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 85 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .137559130869798 3.0862e-08  
a 2.379611756967779 5.4884e-09 au
q 2.052274431871738 7.5018e-08 au
i 9.057055094524708 4.2023e-06 deg
node 18.56555606222222 1.9991e-05 deg
peri 294.6780857220184 2.5728e-05 deg
M 5.09650241904092 1.6663e-05 deg
tp 2458981.518640276089
(2020-May-12.01864028)
6.2051e-05 TDB
period 1340.780193702712
3.67
4.6386e-06
1.27e-08
d
yr
n .2685003863353772 9.2891e-10 deg/d
Q 2.70694908206382 6.2434e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2612  
   data-arc span      44207 days (121.03 yr)  
   first obs. used      1899-10-09  
   last obs. used      2020-10-21  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .48374  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Nov-13 04:32:44  

Additional Information
 Earth MOID = 1.05861 au 
 Jupiter MOID = 2.60191 au 
 T_jup = 3.510 
[ show covariance matrix ]

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 9.1   n/a MPO492750 IRAS observations used: 25
magnitude slope G 0.13   n/a PDS3 (MPC 17257) Fit
diameter diameter 40.992 km 0.694 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  
rotation period rot_per 7.280 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List:
[Debehogne, H.; Zappala, V. (1980) Astron. Astrophys. Suppl. Ser. 42, 85-89.]
[Carlsson, M.; Lagerkvist, C.-I. (1983) Astron. Astrophys. Suppl. Ser. 53, 157-159.]
[Harris, A.W.; Young, J.W. (1989) Icarus 81, 314-364.]
[Pilcher, F.; Higgins, D. (2008) Minor Planet Bull. 35, 147.]
[Pilcher, F. (2011) Minor Planet Bull. 38, 156-158.]
[Franco, L.; Pilcher, F.; Higgins, D.; Durech, J. (2012) Minor Planet Bull. 39, 234-236.]
geometric albedo albedo 0.230   0.021 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  
B-V BV 0.719   0.008 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=10; phase (min.=9.12, mean=12.69, max.=22.47) deg.
U-B UB 0.208   0.024 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=10; phase (min.=9.12, mean=12.69, max.=22.47) 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
SMASSII spectral type spec_B Xc   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)

161 Athor (A876 HA)          Discovered 1876-Apr-19 by Watson, J. C. at Ann Arbor
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 A876 HA = 1961 PF = 1973 YN4 = A899 TA 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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