Electronic Telegram No. 2809
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2011 Q4 (SWAN)
     A possible comet visible on SOHO SWAN spacecraft ultraviolet images has
been reported by two individuals:  Vladimir Bezugly (Dnepropetrovsk, Ukraine)
and Robert D. Matson (Irvine, CA, U.S.A.; via R. H. McNaught, Siding Spring
Observatory).  Among the approximate SWAN positions given below, those with
date fractions given as 0.08 UT are measures by Bezugly, while those given
as 0.5 day are by Matson, and those given as 0.0 UT are measures from
Michael Mattiazzo (Castlemaine, Victoria, Australia) -- reflecting the
poor resolution of the SWAN images.

     2011 UT             R.A. (2000) Decl.       Mag.   Observer
     Aug. 23.08      14 09         -33 04               SWAN
          25.0       14 12.4       -30 19                 "
          25.5       14 14.8       -30 00                 "
          26.5       14 15.1       -29 30                 "
          27.5       14 14.5       -28 18                 "
          28.5       14 13.4       -27 36                 "
          29.5       14 13.9       -26 34                 "
          30.08      14 12         -25 48                 "
          30.5       14 13.0       -25 54                 "
          31.5       14 12.9       -24 45                 "
     Sept. 1.0       14 13.0       -23 39                 "
           1.5       14 13.7       -23 57                 "
           4.38224   14 13 08.69   -21 54 29.1   12.6   McNaught
           4.38295   14 13 08.69   -21 54 27.3   12.6     "
           4.38366   14 13 08.70   -21 54 25.3   13.2     "
           4.38436   14 13 08.70   -21 54 23.8   13.1     "

McNaught's confirming observations on Sept. 4 were obtained with the 0.5-m
Uppsala Schmidt telescope, and they show a large 3'.0 circular coma, strongly
condensed.  Bezugly notified Mattiazzo of his find, and Mattiazzo obtained CCD
images with a Canon 300d camera (+ 300-mm-f.l. telephoto lens) showing the
comet at mag about 11.5; he also obtained astrometry with a Celestron C11
0.28-m f/3.3 Schmidt-Cassegrain reflector on Sept. 4.4 in moonlight.

Additional astrometry, the following preliminary parabolic orbital elements
by G. V. Williams, and an ephemeris appear on MPEC 2011-R22.

     T = 2011 Sept.21.2822 TT         Peri. =   2.2127
                                      Node  = 251.7216  2000.0
     q = 1.125158 AU                  Incl. = 147.0621


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 September 5                 (CBET 2809)              Daniel W. E. Green