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2261 Keeler (1977 HC)
Classification: Main-belt Asteroid          SPK-ID: 2002261
[ 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 2459000.5 (2020-May-31.0) TDB
Reference: JPL 28 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2361983187372322 4.1248e-08  
a 2.378633813048881 9.5031e-09 au
q 1.816804505515204 9.8779e-08 au
i 22.74177135760146 4.4811e-06 deg
node 102.7472924261415 1.0024e-05 deg
peri 99.43670002050484 1.5507e-05 deg
M 272.2102403880384 1.596e-05 deg
tp 2459327.261716127667
(2021-Apr-22.76171613)		 6.0686e-05 TDB
period 1339.953752304524
3.67		 8.0301e-06
2.199e-08		 d
yr
n .268665988942419 1.6101e-09 deg/d
Q 2.940463120582559 1.1748e-08 au
   Orbit Determination Parameters
   # obs. used (total)      2506  
   data-arc span      15915 days (43.57 yr)  
   first obs. used      1977-04-21  
   last obs. used      2020-11-16  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .34836  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Dec-18 02:05:17  

Additional Information
 Earth MOID = .948672 au 
 Jupiter MOID = 2.43148 au 
 T_jup = 3.399 
[ 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 13.0   n/a MPO400017  
diameter diameter 7.323 km 0.209 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  
rotation period rot_per 23.10 h n/a LCDB (Rev. 2020-October); 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:
[Warner, B.D.; Pravec, P.; Kusnirak, P.; Pray, D.P.; et al. (2011) Minor Planet Bull. 38, 3.]
[Pal, A.; Szakats, R.; Kiss, C.; Bodi, A.; et al. (2019) Ap. J. Supl. Ser. 247, id.26.]
geometric albedo albedo 0.266   0.047 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  

2261 Keeler (1977 HC)          Discovered 1977-Apr-20 by Klemola, A. R. at Mount Hamilton
Reference: DISCOVERY.DBLast Updated: 2003-08-29
[ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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