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123P/West-Hartley
Classification: Jupiter-family Comet          SPK-ID: 1000164
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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:
Orbital Elements at Epoch 2457249.5 (2015-Aug-15.0) TDB
Reference: JPL K192/6 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .4492707940975402 1.3728e-07  
a 3.860539534647369 9.9315e-08 au
q 2.126111872271397 5.4784e-07 au
i 15.35434946645353 4.7395e-06 deg
node 46.52937240701016 2.8224e-05 deg
peri 102.9144075103602 4.6823e-05 deg
M 195.0701523726798 1.5717e-05 deg
tp 2458518.808505709129
(2019-Feb-04.30850571)
0.00010669 TDB
period 2770.57833150871
7.59
0.00010691
2.927e-07
d
yr
n .1299367702063717 5.0141e-09 deg/d
Q 5.594967197023341 1.4393e-07 au

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A1 [EST] -3.189044573821657E-9 5.22E-10
A2 [EST] 8.326678176759278E-9 5.8E-10
  Orbit Determination Parameters
   # obs. used (total)      3050  
   data-arc span      3248 days (8.89 yr)  
   first obs. used      2010-09-12  
   last obs. used      2019-08-04  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .64975  
   source      ORB  
   producer      Shantanu Naidu  
   solution date      2020-Jan-13 10:52:40  

Additional Information
 Earth MOID = 1.19564 au 
 Jupiter MOID = .703947 au 
 T_jup = 2.832 
[ 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
comet total magnitude M1 8.2   0.9 K192/6 2 parameter fit from 1030 observations, autocmod 2.8
comet total magnitude slope K1 18.   n/a K192/6 autocmod 2.8
comet nuclear magnitude M2 13.8   0.7 K192/6 from 1937 observations, autocmod 2.8
comet nuclear magnitude slope K2 5.   n/a K192/6 autocmod 2.8
comet nuclear phase coefficient PC 0.03   n/a K192/6 autocmod 2.8
rotation period rot_per 3.7 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Result based on fragmentary lightcurve(s), may be completely wrong.
Published Reference List:
[Kokotankekova, R.; Snodgrass, C.; Lacerda, P.; Green S.F.; et al. (2017) Mon. Not. Royal Ast. Soc. 471, 2974-3007.]

123P/West-Hartley          Discovered 1989-May-11 by West, Richard M. at European Southern Observatory
discovered on plate/photo taken on 3/14
Reference: comet.disLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 Perihelion 
Year
(est.)
 New-Style 
Desig
Roman
 Numeral 
Year/
 Letter 
 1996.3   123P/1995 S2       
 1988.8   123P/1989 E3   1988 XVI   1989k 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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