On the possible identity of comet P/2006 T1 (Levy) and C/1743 C1

Last updated and extended: 18 December 2011


After the discovery of comet P/2006 T1 I quickly tried to find possible matches with historic comets. However, from the behaviour of the comet and the circumstances of discovery it was clear that it must have undergone an outburst that brought it into visual range. This was also supported by the light curve and also the astrometry - there sometimes seemed to be a shift of the central condensation that lead to consistently systematic trends in certain periods of its visibility.

I was not able to find recent comets that could be identified with the comet but thought to try backward integration until about 1400 AD. I then checked possible candidates in history and indeed found one comet that was quite close to the backward integrated orbit: C/1743 C1.

C/1743 C1 was seen for 18 days in February 1743, due to a very close approach to Earth. The estimated magnitude was about 3. The accepted orbit is by Olbers, who took 4 positions to calculate a parabolic orbit, however, the inclination of 2° lead to the suspicion that the comet might be of short period.

In 2006 I extracted the observations from the original sources and was able to find 15 observations. Unfortunately, the solution was also not conclusive whether the orbit is indeed of short period.

Below I present one backward integration of the P/2006 T1 data with the 1743 C1 data residuals. Due to the long integration and some close approaches one can not expect to receive a direct link of both apparitions. Since the comet seems to tend to outbursts one can expect the existence of non-gravitational forces which would also add to the uncertainties here.

What can be seen, however, is that the integrated orbit also shows a close approach to Earth in January 1743, just like 1743 C1. It has to be noted that due to the many perturbations the P/2006 T1 orbit is nearly chaotic, i.e. ex- or inclusion of single observations will change the resulting orbit dramatically. It is hoped that with a possible recovery of P/2006 T1 this uncertainty can be decreased.

P/2006 T1 (Levy)                                         C/1743 C1
Meyer                                                    Meyer
Perihelion 1743 Jan 1.891690 TT                          Perihelion 1743 Jan 11.262468 TT
Epoch 1743 Jan 11.0 TT                                   Epoch 1743 Mar  1.0 TT
(2000.0)                                                (2000.0)
Peri    38.66287                                         Peri   20.02846
Node    52.90363                                         Node   76.20336
Incl    5.73461                                          Incl    2.28894
q       0.87316119                                       q       0.83554410
e       0.7149101                                        e       1.0
P       5.36 
278 observations 2006 Oct. 2-Nov. 23                     10 observations 1743 Feb. 10 - 28
RMS error 0.971 arcseconds                               RMS error 566 arcseconds
Earth MOID: 0.0096   Ju: 0.3240                          Earth MOID: 0.0180    Ju: 0.0019

A forced elliptical solution moves the angular elements slightly farther away from the 2006 data, but the perihelion time shifts to January 8, closer to the 2006 data solution.

Below are given the residuals. One can see that they are relatively large for 1743, but given the difference in the angular elements and perihelion time, this is still very good.

One can conclude that a solution exists that brings comet P/2006 T1 close to comet C/1743 C1. Additionally, the backward integration also shows a close approach to Earth, supporting the suggested identity. However, it seems likely that a firm establishment of this link will never be possible because several perturbations by Jupiter (and maybe Earth) as well as non-gravitational forces have lead to a nearly chaotic behaviour of the orbit. It will be interesting to see whether there will be an improvement of this orbit when the comet will be recovered - something that is not for sure.

I welcome any hints, suggestions, and ideas. I intend to extend this page with more details as time permits.

430210 548(3.7d-  15d+)   061007 361  .77-  1.6-    061017 G92( 2.9-  3.3+)
430212 552(9.8d- 5218-)   061007 361  1.5-  .43+    061017 G92( 2.9-  2.6+)
430213 007( 11d- 5.6d-)   061007 361  .21-  .42+    061018 379  .92+  .72- 
430214 552( 11d- 9.1d-)   061008 585( 2.2-  .55+)   061018 379  1.1+  .04+ 
430214 548( 11d- 9.6d-)   061008 585( 6.1-  2.6+)   061019 G92( .85-  4.8+)
430215 548( 11d-  11d-)   061008 585  .73-  1.8+    061019 G92( 3.9-  2.7+)
430216 548(9.8d-  13d-)   061008 585  .68-  .79+    061020 A79  .37+  1.2+ 
430218 007(9.3d-  14d-)   061008 585  .40+  .27-    061020 A79  .14+  .76+ 
430219 548(7.5d-  15d-)   061008 D88  1.4-  .84+    061020 A79  1.1+  .74+ 
430220 552(7.3d-  15d-)   061008 D88  .90-  .90+    061020 A79  .53-  1.0+ 
430221 545(5.6d-  16d-)   061008 D88  .80-  .55+    061020 A79  .12+  .13+ 
430221 552(6.7d-  15d-)   061008 349  .69-  .59+    061020 J63( 1.2-  1.8+)
430223 552(5.7d-  15d-)   061008 349  .69-  .69+    061020 J63( .90-  2.8-)
430226 552(4.3d-  15d-)   061008 349  .52-  .78+    061020 J63  .00   .22+ 
430228 552(3.5d-  14d-)   061008 379  .06+  .35-    061020 G92( 4.3-  1.7+)
061002 G92( .79+  1.9-)   061008 367  .96-  .32+    061020 G92( 3.3-  2.5+)
061002 G92  .02+  .56-    061008 367  .44-  .47+    061020 G92( 3.6-  .94+)
061002 G92  .65+  1.4-    061008 367  .95-  .22+    061020 G92( 3.6-  1.5+)
061002 G92  .17-  .10-    061008 379  .29+  .32-    061020 372  .09-  .34- 
061002 G92  1.0+  1.1-    061009 585( 2.3-  .05-)   061020 349  .11+  .58+ 
061002 G92  .32+  .23-    061009 585( 1.7-  1.1-)   061020 349  .12+  .48+ 
061003 461  .14-  .53+    061009 585  1.2-  .28-    061020 372  .36-  .27- 
061003 461  .04+  .38+    061009 585  .27-  .36-    061020 349  .02-  .29+ 
061003 461  .01+  .57+    061009 585  1.3-  .14-    061020 372  .24-  .42- 
061003 461  .19+  .46+    061009 585  .52-  .78+    061021 442( 1.2-  1.9+)
061003 461  1.6+  .62-    061009 585  .40-  .82-    061021 232  .37-  .53+ 
061003 J95  .24+  .07-    061009 585  .78+  1.2+    061021 232  .99-  .12+ 
061003 J95  .07-  .22-    061009 585  .50+  1.1+    061021 232( 2.7-  1.8-)
061003 J95  .00   .31-    061009 349  .40-  .30+    061021 G92  1.5-  1.3+ 
061003 J95  .09-  .23-    061009 349  .37-  .22+    061021 G92( 2.2-  1.6+)
061003 J95  .28-  .14-    061009 349  .05-  .13+    061021 G92( 4.7-  2.8+)
061003 J95  .31-  .46-    061009 379  .04+  .97-    061021 G92( 2.6-  3.3+)
061003 J95  .06-  .48-    061009 379  .81+  1.6-    061021 448  1.2-  .22+ 
061003 J95  .06-  .32-    061009 379  .03+  1.4-    061021 G96  .44+  .39- 
061003 J77  .34-  1.1-    061011 H06  .92-  .25+    061021 G96  .23+  .36- 
061003 J77  .50+  .31-    061011 H06  .69-  .22-    061021 G96  .22+  .57- 
061003 J77  .75+  1.1-    061011 673( 2.2+  .38-)   061021 G96  .48+  .36- 
061003 J77  .27-  .24-    061011 673  1.5+  .75-    061021 448  .31-  .13- 
061003 J77  .74+  .35-    061011 673  1.5+  .96-    061021 448  .29-  .13+ 
061003 J77  .50-  .00     061011 673  1.7+  .78-    061021 361  .62+  1.3- 
061003 J77  .12+  .00     061012 J95  .18-  .01-    061021 361( 1.8+  2.5-)
061003 J77  .57-  .02+    061012 J95  .48-  .48+    061022 J95  .73-  .49+ 
061003 J77  1.1-  .25+    061012 J95  .26-  .13+    061022 J95  .21-  .01+ 
061003 G92  .10+  .53+    061012 939( 4.9+  .81-)   061022 J95  .03+  .17+ 
061003 854  1.1-  1.0+    061012 939( .63+  2.5+)   061022 G92( 1.2-  3.3+)
061003 854( 2.3+  .33+)   061012 939( 3.7-  6.2+)   061022 G92( 1.4-  1.5+)
061003 G92  .40+  .61-    061012 850  .68-  .06-    061022 G92( 2.6-  .36+)
061003 854  1.1+  .02+    061012 850  .81-  .51+    061022 G92( 3.5-  1.3+)
061003 H06  .63+  .35-    061012 850  1.1-  .35+    061023 442  .12-  .31- 
061003 G92  .65+  .03+    061012 850  .60-  .32+    061023 442( 3.0-  .24-)
061003 H06  .66+  .34+    061012 850  1.0-  .81+    061023 H06  1.4-  .35+ 
061003 H06  .15-  .01-    061012 349  .75-  1.0+    061023 H06  .03-  .62+ 
061003 H06  .31+  .00     061012 349  1.1-  .76+    061023 372  1.9-  .14+ 
061003 H06  .43+  .07-    061013 J63( 2.5-  1.5+)   061023 372  1.5-  .66+ 
061003 H06  .09+  .29-    061013 J63  .02-  1.2-    061024 850  .90-  .19+ 
061003 G92  .28+  .52+    061013 J63( .12+  2.5-)   061024 850  1.6-  .45+ 
061003 G92  .45+  .24+    061013 850  .07+  .45+    061024 850  .45-  .51+ 
061003 G92  1.2+  .68-    061013 850  .27-  .15+    061025 442( 4.8-  4.0+)
061003 G92  .61+  .02-    061013 850  .10+  .40+    061025 442( 4.7-  4.2+)
061003 G92  .17+  .93+    061013 850  .21+  .15+    061025 442( 3.8-  .54+)
061003 G92  .36+  .29+    061013 850  .04-  .15+    061025 442( 3.1-  .56+)
061003 G92  .12-  .67+    061013 850  .10-  .21+    061025 H06  1.6-  .22+ 
061003 G92  .17+  1.1+    061013 H06  .86+  .51-    061025 H06( 2.3-  .82+)
061003 G92  .00   .59+    061013 H06  .78+  .20-    061025 372  1.6-  .20+ 
061003 G92  .58+  .12+    061013 448  .00   .08-    061025 372  1.1-  .37+ 
061003 G92  .04+  .16+    061013 448  .63+  .48-    061025 372  .73-  .28+ 
061003 G92  .62-  .60-    061013 448  .90-  .17+    061025 349  1.2-  .08+ 
061003 G92  .27-  1.1-    061013 448  .33+  .26-    061025 349  1.3-  .33+ 
061003 G92  .71-  .51+    061014 349  .82+  .12-    061025 349  1.2-  .17+ 
061003 G92  .36-  .25+    061014 349  .91+  .08-    061027 J95  1.4-  .86+ 
061003 G92  .38+  .11-    061014 349  .89+  .16-    061027 J95  1.0-  .26+ 
061003 361  .10+  1.1+    061014 D70  1.1+  .45-    061027 J95  1.8-  .65+ 
061003 361  1.1-  .38+    061014 D70  1.7+  .43+    061027 H06  1.5-  .31+ 
061003 361  .24+  1.1-    061014 D70  1.4+  .79+    061027 H06( 2.0-  1.1+)
061003 361  .06-  .48-    061015 118  1.1+  .53-    061027 448  .54+  .13- 
061003 361  .88-  .13-    061015 118  1.2+  .59-    061027 448  .34-  .20- 
061003 361  1.0-  .23+    061015 118  .69+  .34-    061027 448  .74-  .11+ 
061004 J95  .30-  .07-    061015 461  1.4+  .43-    061028 118  1.6-  .58+ 
061004 J95  .26-  .03-    061015 461  1.0+  .14-    061028 118  .74-  .31+ 
061004 J95  .18-  .10+    061015 461  1.0+  .00     061029 H06( 2.4-  1.2+)
061004 J77  .07+  .42-    061015 118  .93+  .51-    061029 H06  .69-  .08- 
061004 J77  .11-  .81-    061015 461  1.2+  .48-    061031 H07( 3.5-  .72+)
061004 J77  .15+  .06-    061015 461  1.3+  .29-    061031 H07  .62-  .56+ 
061004 J77  .69-  .08-    061015 461  1.0+  .27-    061031 H07  .91+  .17- 
061004 850  .19-  .49+    061015 461  1.1+  .24-    061103 J95( 3.9-  1.5+)
061004 850  .24-  .09+    061015 461  1.3+  .54-    061103 J95( 3.2-  1.5+)
061004 850  .05-  .05+    061015 118  1.0+  .42-    061103 J95( 4.5-  1.8+)
061004 850  .64-  .28+    061015 461  .99+  .12+    061103 850( 3.9-  1.7+)
061004 H07( 2.8-  1.3+)   061015 349  .75+  .03-    061103 850( 3.5-  1.5+)
061004 H07( 2.0-  1.1+)   061015 349  .69+  .17+    061103 850( 4.2-  1.8+)
061004 H07  1.4-  .74+    061015 349  .39+  .23+    061103 850( 3.0-  3.9+)
061004 H06  .47-  .26+    061015 361  1.1+  1.3-    061108 349( 4.4-  1.7+)
061004 H06  .08-  .31-    061015 361( 2.5+  .90-)   061108 349( 4.4-  1.5+)
061004 H06  .26-  .19-    061015 372  .42+  .58-    061109 850  1.5-  .56+ 
061005 850  .28-  .35+    061015 361  1.3+  1.3-    061109 850  1.4+  .51- 
061005 850  .36-  .22+    061015 372  .36+  .47-    061109 850( 2.1+  .21+)
061005 850  .47-  .14+    061015 361  .40+  .47-    061110 H06  1.0+  .61- 
061005 850  .14-  .09-    061015 372  .45+  .61-    061110 673( 2.7+  .01-)
061006 204  .14-  .04-    061015 361  .07+  .41+    061110 673( 3.1+  .29-)
061006 204  .24-  .13-    061015 361  1.1+  .37+    061110 673( 3.0+  1.2-)
061006 204  .14-  .00     061015 361  .52+  1.6-    061110 673( 2.9+  1.8-)
061006 442( 2.0+  .92-)   061015 361  .20+  .31+    061113 H06  .24+  .21+ 
061006 442( 2.4+  1.0-)   061015 361  1.7+  .43+    061116 H06  1.9+  .02- 
061006 J63  .89+  .05-    061016 104  1.2+  .33-    061117 H06  .87+  .03+ 
061006 J63  .26+  .65-    061016 104  1.3+  .20-    061118 232  .46-  .92- 
061006 J63  1.0-  1.1-    061016 143  .70+  .02+    061118 232  .56-  .80- 
061006 372  .24+  1.0+    061016 143  .79+  .07+    061118 232  .70-  .71- 
061006 372  .17-  .07-    061016 143  .58+  .28-    061118 J95( 2.1+  .71-)
061006 372  .45-  .92+    061016 H06  .33+  .12-    061118 J95  1.2+  .71- 
061006 372  .12-  .18-    061016 H06  .84+  .11-    061119 G92  .01+  .22- 
061007 J95  .43-  .25+    061016 693  1.4+  .40-    061119 G92( 2.6+  .59-)
061007 J95  .57-  .02+    061016 693  1.4+  .15-    061121 850  .15-  1.0+ 
061007 J95  .48-  .00     061016 693  1.6+  .31-    061121 850( 2.3+  1.3-)
061007 J95  .53-  .19+    061016 693  1.4+  .95+    061122 850( 5.9-  .37+)
061007 J95  .56-  .08-    061017 048  .23+  .23-    061122 850  .75-  .10- 
061007 349  .62-  .44+    061017 048  .48+  .41-    061123 850  .23-  .72- 
061007 349  .59-  .28+    061017 048  .63+  .62-    061123 850  .87+  .40+ 
061007 349  .70-  .11+    061017 048  .55+  .17-    061123 850  .02+  .46+ 
061007 300  1.2-  .15+    061017 048  .73+  .79-    061123 850( 2.5-  .88+)
061007 300( 1.4-  1.6+)   061017 G92( 3.0-  1.5+)   
061007 300  1.3-  1.0+    061017 G92( 1.9-  4.0+)   

The comet was recovered on 2011 December 17. A backwards integrated orbit now gives:

	P/2006 T1
   Perihelion 1742 Nov 23.727124 TT = 17:27:03 (JD 2357639.227124)
Epoch 1743 Jan 11.0 TT = JDT 2357687.5   Earth MOID: 0.4165   Ju: 0.3703
M   7.11592              (2000.0)        Ma: 0.0580
n   0.14741045     Peri.   64.78774      0.05267287     -0.99816363     
a   3.54909147     Node    22.25435      0.88543174      0.03282953     
e   0.6077770      Incl.    4.53055      0.46177503      0.05090754     
P   6.69           M(T) 12.5    K  10.0   q 1.39203525  Q 5.70614768
From 287 observations 2006 Oct. 2-2011 Dec. 17; mean residual 0".681.

This does not look promising. I will re-check the situation after the 2011/2012 apparition is over.

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Copyright © 2010 by M. Meyer

If you have any questions, please email me (maik@comethunter.de).