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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 2456640.5 (2013-Dec-14.0) TDB
Reference: JPL K192/3 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .4620723499955288 2.0117e-07  
a 3.735635296103672 5.0857e-07 au
q 2.009501516106805 1.0184e-06 au
i 6.254600612498066 6.8232e-06 deg
node 210.5592990505777 0.00016723 deg
peri 192.7503248685438 0.00017232 deg
M 95.74877180455672 1.621e-05 deg
tp 2455939.083717557088
(2012-Jan-12.58371756)
9.0134e-05 TDB
period 2637.212539862901
7.22
0.00053855
1.474e-06
d
yr
n .1365077689258656 2.7876e-08 deg/d
Q 5.461769076100539 7.4357e-07 au

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A1 [EST] 6.295169713556472E-10 1.43E-10
A2 [EST] 4.816593367225619E-10 1.683E-11
A3 [EST] -4.500285579884824E-10 7.356E-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)      4698  
   data-arc span      3106 days (8.50 yr)  
   first obs. used      2011-05-03  
   last obs. used      2019-11-03  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      1  
   norm. resid. RMS      .60058  
   source      ORB  
   producer      Javier Roa  
   solution date      2019-Nov-07 14:29:19  

Additional Information
 Earth MOID = 1.01837 au 
 Jupiter MOID = .0194396 au 
 T_jup = 2.887 
 Nongrav. accels. using CO driven g(r) 
[ 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 8.4   0.9 K192/3 2 parameter fit from 1076 observations, autocmod 2.8
comet total magnitude slope K1 15.   n/a K192/3 autocmod 2.8
comet nuclear magnitude M2 12.5   0.7 K192/3 from 3444 observations, autocmod 2.8
comet nuclear magnitude slope K2 5.   n/a K192/3 autocmod 2.8
comet nuclear phase coefficient PC 0.03   n/a K192/3 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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