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121P/Shoemaker-Holt 2
Classification: Jupiter-family Comet          SPK-ID: 1000141
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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Orbital Elements at Epoch 2453237.5 (2004-Aug-20.0) TDB
Reference: JPL 42 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .3384566137765764 1.1932e-07  
a 4.002945176938433 9.0147e-08 au
q 2.648121907218573 4.7587e-07 au
i 17.71778365749723 1.0729e-05 deg
node 99.66992336183945 2.5236e-05 deg
peri 6.229876733146102 1.7828e-05 deg
M 358.4351874021517 1.453e-05 deg
tp 2453250.215332557404
(2004-Sep-01.71533256)
0.00011822 TDB
period 2925.283019167699
8.01
9.8817e-05
2.705e-07
d
yr
n .1230650154672648 4.1572e-09 deg/d
Q 5.357768446658294 1.2066e-07 au
  Orbit Determination Parameters
   # obs. used (total)      595  
   data-arc span      11549 days (31.62 yr)  
   first obs. used      1989-03-04  
   last obs. used      2020-10-16  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .65062  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Oct-18 17:46:45  

Additional Information
 Earth MOID = 1.6647 au 
 Jupiter MOID = .114586 au 
 T_jup = 2.872 
[ 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 5.6   1. 42 2 parameter fit from 278 observations, autocmod 2.8
comet total magnitude slope K1 20.25   n/a 42 autocmod 2.8
comet nuclear magnitude M2 12.5   0.5 42 from 134 observations, autocmod 2.8
comet nuclear magnitude slope K2 5.   n/a 42 autocmod 2.8
comet nuclear phase coefficient PC 0.03   n/a 42 autocmod 2.8
diameter diameter 3.24 km n/a Lamy,P.L.,Toth,I.,Fernandez,Y.R.,Weaver,H.A. (2004) Comets II, pp. 223-264  

121P/Shoemaker-Holt 2          Discovered 1989-Mar-09 by Shoemaker, Carolyn & Eugene, & Holt, Henry at Palomar Mountain Observatory, California
discovered on plate/photo taken on discovery date
Reference: comet.disLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 Perihelion 
Year
(est.)
 New-Style 
Desig
Roman
 Numeral 
Year/
 Letter 
 1996.7   121P/1995 Q3       
 1988.7   121P/1989 E2   1988 XI   1989j 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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