[IAUC] IAUC 8729: C/2006 M4 [25139-2007/05-R1]

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                                                  Circular No. 8729
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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COMET C/2006 M4 (SWAN)
     R. D. Matson, Irvine, CA; and M. Mattiazzo, Adelaide, S.
Australia, report independently that they found images of a moving
object at small solar elongations on SOHO/SWAN images from late
June, and both men asked southern-hemisphere observers to try
confirming a possible comet in that vicinity (averaged SWAN
positions from Matson and Mattiazzo are provided below).  In
response to Mattiazzo's request, T. Lovejoy (Thornlands, Qld.,
Australia) found an image of the suspected comet on CCD frames
taken on June 30 with a Canon 350D camera (+ 100-mm-focal-length
f/3.5 lens), noting the object to have a distinct greenish hue and
an apparent circular coma of diameter about 0'.5.  Confirming
images taken by R. H. McNaught with the 0.5-m Uppsala Schmidt
telescope on July 12 show a strongly condensed coma and a tail 80"
long in p.a. 205 deg.

     2006 UT             R.A. (2000) Decl.       Mag.   Observer
     June 20          8 42.0       - 9 29               SWAN
          22          8 44.0       - 8 48                 "
          25          8 46.8       - 8 00                 "
          29          8 50.0       - 6 09                 "
          30.363      8 52.49      - 6 20.8      12     Lovejoy
     July  2          8 52.4       - 5 14               SWAN
           4          8 54.2       - 4 38                 "
           5          8 54.8       - 3 42                 "
          12.35695    9 05 59.07   - 1 55 43.8   12.3   McNaught
          12.35925    9 05 59.27   - 1 55 41.0            "
          12.36157    9 05 59.46   - 1 55 38.5            "
          12.36387    9 05 59.63   - 1 55 35.6            "

     The ephemeris below is provided to aid observers, taken from
very uncertain parabolic orbital elements (T = 2006 Aug. 24.2 TT, q
= 0.132 AU, Peri. = 112.9, Node = 162.6, i = 98.8, equinox 2000.0).

2006 TT     R. A. (2000) Decl.   Delta     r    Elong. Phase   Mag.
July  4     8 56.02   - 4 43.2   1.994   1.398   41.1   28.6   13.0
      9     9 01.84   - 3 03.4   1.958   1.299   37.0   28.1   12.6
     14     9 08.08   - 1 22.2   1.915   1.196   32.9   27.5   12.2
     19     9 14.74   + 0 22.2   1.864   1.089   28.7   26.7   11.7
     24     9 21.88   + 2 12.0   1.805   0.977   24.6   25.6   11.2

                      (C) Copyright 2006 CBAT
2006 July 12                   (8729)            Daniel W. E. Green