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117P/Helin-Roman-Alu 1
Classification: Jupiter-family Comet          SPK-ID: 1000121
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 2456839.5 (2014-Jul-01.0) TDB
Reference: JPL K222/1 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2538825519020135 2.8896e-07  
a 4.096313858311542 2.7311e-06 au
q 3.056331242571825 9.4031e-07 au
i 8.69719019665926 7.3951e-06 deg
node 58.89513095886191 4.5151e-05 deg
peri 222.6753452318465 6.686e-05 deg
M 11.39874839182471 3.7421e-05 deg
tp 2456743.616709269495
(2014-Mar-27.11670927)
0.00023762 TDB
period 3028.225860984741
8.29
0.0030284
8.291e-06
d
yr
n .1188814892040228 1.1889e-07 deg/d
Q 5.136296474051258 3.4244e-06 au

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A1 [EST] 9.956335156672765E-8 2.31E-8
A2 [EST] 2.995867697873739E-8 5.475E-9
  Orbit Determination Parameters
   # obs. used (total)      2532  
   data-arc span      3106 days (8.50 yr)  
   first obs. used      2010-11-03  
   last obs. used      2019-05-06  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      2  
   norm. resid. RMS      .62069  
   source      ORB  
   producer      Davide Farnocchia  
   solution date      2019-May-15 16:19:06  

Additional Information
 Earth MOID = 2.04743 au 
 Jupiter MOID = .257281 au 
 T_jup = 2.967 
[ 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 7.3   0.8 K222/1 2 parameter fit from 567 observations, autocmod 2.6q
comet total magnitude slope K1 12.   n/a K222/1 autocmod 2.6q
comet nuclear magnitude M2 11.4   0.5 K222/1 from 1817 observations, autocmod 2.6q
comet nuclear magnitude slope K2 5.   n/a K222/1 autocmod 2.6q
comet nuclear phase coefficient PC 0.03   n/a K222/1 autocmod 2.6q
diameter diameter 9 km n/a Scotti,J (1994) BAAS 26:1375  

117P/Helin-Roman-Alu 1          Discovered 1989-Oct-02 by Helin, Eleanor, Roman, Brian and Alu, Jeff at Palomar Mountain Observatory, California
Reference: comet.disLast Updated: 2003-08-29

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Alternate Designations
 Perihelion 
Year
(est.)
 New-Style 
Desig
Roman
 Numeral 
Year/
 Letter 
 1989.4   117P/1989 T2   1987 XXXVII   1989w 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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