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78P/Gehrels 2
Classification: Jupiter-family Comet          SPK-ID: 1000030
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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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 2456966.5 (2014-Nov-05.0) TDB
Reference: JPL K192/19 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .4616643215463381 1.8128e-07  
a 3.736348077733531 3.4971e-07 au
q 2.011409477365716 8.5996e-07 au
i 6.252821276087988 5.4014e-06 deg
node 210.5626210607211 4.1185e-05 deg
peri 192.7561909929703 5.0034e-05 deg
M 140.2700250333011 1.3621e-05 deg
tp 2455938.645141657307
(2012-Jan-12.14514166)
0.00011064 TDB
period 2637.967369832023
7.22
0.00037036
1.014e-06
d
yr
n .1364687084900991 1.9159e-08 deg/d
Q 5.461286678101346 5.1116e-07 au

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A1 [EST] -8.903890485206713E-10 1.097E-10
A2 [EST] 3.472101564500642E-10 1.13E-11
ALN [SET] .0408373333128795 n/a
NK [SET] 2.6 n/a
NM [SET] 2. n/a
NN [SET] 3. n/a
R0 [SET] 5. n/a
  Orbit Determination Parameters
   # obs. used (total)      5523  
   data-arc span      3311 days (9.07 yr)  
   first obs. used      2011-05-03  
   last obs. used      2020-05-26  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .60195  
   source      ORB  
   producer      Javier Roa  
   solution date      2020-Nov-02 12:51:03  

Additional Information
 Earth MOID = 1.02026 au 
 Jupiter MOID = .0215566 au 
 T_jup = 2.887 
[ 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 8.8   0.8 K192/19 2 parameter fit from 1800 observations, autocmod 2.8
comet total magnitude slope K1 13.75   n/a K192/19 autocmod 2.8
comet nuclear magnitude M2 12.6   0.7 K192/19 from 3507 observations, autocmod 2.8
comet nuclear magnitude slope K2 5.   n/a K192/19 autocmod 2.8
comet nuclear phase coefficient PC 0.03   n/a K192/19 autocmod 2.8

78P/Gehrels 2          Discovered 1973-Sep-29 by Gehrels, Tom
discovered on plate/photo taken on discovery date as well as 9/30, 10/4
Reference: comet.disLast Updated: 2003-08-29

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Alternate Designations
 Perihelion 
Year
(est.)
 New-Style 
Desig
Roman
 Numeral 
Year/
 Letter 
 1990.4       1989 XVII   1989n 
 1983.1   78P/1981 L1   1981 XVII   1981f 
 1975.9   78P/1973 S1   1973 XI   1973n 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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