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21P/Giacobini-Zinner
Classification: Jupiter-family Comet [NEO]          SPK-ID: 1000032
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]
:
Orbital Elements at Epoch 2456498.5 (2013-Jul-25.0) TDB
Reference: JPL K123/6 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .7068178874382801 1.2577e-07  
a 3.515549653876195 1.1447e-07 AU
q 1.030696274339046 4.3624e-07 AU
i 31.90810098618194 1.6905e-05 deg
node 195.3970144851808 3.3699e-05 deg
peri 172.5844249090343 4.2816e-05 deg
M 79.15473085623789 9.3975e-06 deg
tp 2455969.125939250444
(2012-Feb-11.62593925)
4.495e-05 JED
period 2407.621879429606
6.59
0.00011759
3.219e-07
d
yr
n .1495251405861489 7.303e-09 deg/d
Q 6.000403033413344 1.9538e-07 AU

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A1 [EST] 3.35287747807868E-9 4.433E-11
A2 [EST] -4.292906732981725E-10 1.511E-11
A3 [EST] -9.567846728869522E-10 4.466E-11
DT [EST] -32.77074470563737 .6476
  Orbit Determination Parameters
   # obs. used (total)      1538  
   data-arc span      5550 days (15.20 yr)  
   first obs. used      1998-01-20  
   last obs. used      2013-04-01  
   planetary ephem.      DE405  
   SB-pert. ephem.      SB405-CPV-2  
   condition code      0  
   fit RMS      .77933  
   data source      ORB  
   producer      Ryan S. Park  
   solution date      2013-Jul-15 11:48:17  

Additional Information
 Earth MOID = .0353945 AU 
 T_jup = 2.467 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
comet total magnitude M1 10.5 mag 1. K123/6 2 parameter fit from 470 observations, autocmod 2.5c
comet total magnitude slope K1 15.   n/a K123/6 autocmod 2.5c
diameter diameter 2.0 km n/a Lamy,P.L.,Toth,I.,Fernandez,Y.R.,Weaver,H.A. (2004) Comets II, pp. 223-264  

21P/Giacobini-Zinner          Discovered 1900-Dec-20 by Giacobini, M. at Nice Observatory, France
Reference: comet.disLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 Perihelion 
Year
(est.)
 New-Style 
Desig
Roman
 Numeral 
Year/
 Letter 
 1992.3       1992 IX   1991m 
 1985.7       1985 XIII   1984e 
 1979.2       1979 III   1978h 
 1972.6       1972 VI   1972d 
 1966.0       1966 I   1965g 
 1959.4       1959 VIII   1959b 
 1946.2       1946 V   1946c 
 1939.6       1940 I   1939l 
 1933.0       1933 III   1933c 
 1926.4       1926 VI   1926e 
 1913.2   21P/1913 U1   1913 V   1913e 
 1900.1   21P/1900 Y1   1900 III   1900c 
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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