Electronic Telegram No. 3193
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 P/2012 O3 (McNAUGHT)
     R. H. McNaught, Australian National University, reports his discovery of
a comet on CCD images obtained with the 0.5-m Uppsala Schmidt telescope at
Siding Spring (discovery astrometry tabulated below); the comet's images look
soft to the eye and show a consistently larger FWHM than the nearby stars
(4".8 vs. 3".9).  Five staked 60-s follow-up images from July 24.6 UT in
reasonable seeing show the object to appear nearly asteroidal but with a very
faint coma of diameter 0'.4 that give the appearance of "soft" edges to
object's image.  Similar stacked images by McNaught on July 25.5 again reveal
a small, faint coma of mag 17.7-17.8.  After posting on the Minor Planet
Center's NEOCP webpage, G. Sostero, N. Howes, and E. Guido report that
fourteen 60-s stacked R-band images obtained remotely with the 2.0-m f/10
"Faulkes Telescope North" at Haleakala on July 24.47 in good seeing
conditions show a sharp central condensation surrounded by a faint coma
nearly 5" in diameter, elongated toward p.a. 25 deg.

     2012 UT             R.A. (2000) Decl.       Mag.   Observer
     July 23.69130   21 51 38.65   -35 45 38.8   17.9   McNaught
          23.70275   21 51 38.39   -35 45 27.1   18.0     "
          23.71414   21 51 38.05   -35 45 16.7   18.0     "
          23.72563   21 51 37.83   -35 45 03.6   17.7     "

The available astrometry, the following preliminary elliptical orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2012-O36.

     T = 2012 Aug. 15.6087 TT         Peri. = 343.3046
     e = 0.648315                     Node  = 337.0517  2000.0
     q = 1.599900 AU                  Incl. =  16.4636
       a =  4.549246 AU    n = 0.1015769    P =   9.70 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 July 26                     (CBET 3193)              Daniel W. E. Green