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JPL Small-Body Database Browser
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238P/Read
Classification: Encke-type Comet          SPK-ID: 1001676
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | 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 2454616.5 (2008-May-30.0) TDB
Reference: JPL 17 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2531969535960581 5.469e-07  
a 3.161984976656008 4.0958e-07 au
q 2.361380013250204 1.9414e-06 au
i 1.266163692965964 2.4294e-05 deg
node 51.62749710582454 0.00043601 deg
peri 325.6241461267416 0.00045372 deg
M 181.8403077456012 8.2564e-05 deg
tp 2455632.854192979267
(2011-Mar-12.35419298)
0.00061836 TDB
period 2053.705329430385
5.62
0.00039903
1.092e-06
d
yr
n .1752929180447954 3.4059e-08 deg/d
Q 3.962589940061813 5.1328e-07 au

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A1 [EST] 2.423474469114649E-9 1.078E-9
A2 [EST] -5.449707315275096E-11 6.433E-11
  Orbit Determination Parameters
   # obs. used (total)      214  
   data-arc span      4407 days (12.07 yr)  
   first obs. used      2005-10-23  
   last obs. used      2017-11-16  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      1  
   norm. resid. RMS      .70869  
   source      ORB  
   producer      Otto Matic  
   solution date      2017-Dec-02 17:14:49  

Additional Information
 Earth MOID = 1.36176 au 
 Jupiter MOID = 1.4998 au 
 T_jup = 3.154 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
comet total magnitude M1 10.1   0.7 17 2 parameter fit from 111 observations, autocmod 2.6k
comet total magnitude slope K1 24.   n/a 17 autocmod 2.6k
comet nuclear magnitude M2 17.6   01. 17 from 78 observations, autocmod 2.6k
comet nuclear magnitude slope K2 5.   n/a 17 autocmod 2.6k
comet nuclear phase coefficient PC 0.03   n/a 17 autocmod 2.6k

[ show close-approach data ]
Alternate Designations
 Perihelion 
Year
(est.)
 New-Style 
Desig
Roman
 Numeral 
Year/
 Letter 
 2011.2   238P/2010 N2       
 2005.6   238P/2005 U1       
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ]
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