Electronic Telegram No. 3462
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/2013 G2 (McNAUGHT)
     R. H. McNaught reports his discovery of a comet on CCD images taken with
the 0.5-m Uppsala Schmidt telescope at Siding Spring (discovery observations
tabulated below), noting a coma of diameter 14" with moderately diffuse
condensation and a diffuse tail 0'.4 long in p.a. 230 deg.  After posting on
the Minor Planet Center's NEOCP webpage, other CCD astrometrists have also
commented on the object's cometary appearance.  T. Lister writes that
exposures taken by E. J. Christensen, S. M. Larson, and T. Lister with the
1.0-m f/8 Las Cumbres Observatory Global Telescope at Cerro Tololo on Apr. 9.4
UT shows a coma of diameter approximately 8" with elongation to the southwest.
Lister adds that six stacked 180-s exposures taken on Apr. 9.7 with the 2.0-m
f/10 "Faulkes Telescope South" at Siding Spring show a coma of diameter about
7".5.  H. Sato (Tokyo, Japan; remotely using a 0.51-m f/6.8 astrograph of the
iTelescope Observatory at Siding Spring; six stacked 60-s images from Apr.
9.7) notes a strongly condensed coma 20" in diameter with total V-band
magnitude, as measured within a circular aperture of radius 9".9, of 16.8; it
also showed a fan-like tail 50" long toward p.a. 220 degrees.  R. Ligustri
(Talmassons, Udine, Italy; remotely with a 0.50-m f/4.5 reflector of the
iTelescope Observatory at Siding Spring; Apr. 10.8) finds a coma of size
about 15" that is elongated toward p.a. 230 deg.

     2013 UT             R.A. (2000) Decl.       Mag.   Observer
     Apr.  8.71616   20 26 23.56   -37 51 04.1   17.0   McNaught
           8.72686   20 26 23.28   -37 50 56.8   16.9     "
           8.73750   20 26 22.96   -37 50 51.2   16.7     "
           8.74819   20 26 22.81   -37 50 45.3   16.7     "

The available astrometry, the following preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2013-G39.

     T = 2012 Dec.  1.1790 TT         Peri. = 289.4759
                                      Node  = 274.1706  2000.0
     q = 2.049029 AU                  Incl. =  94.8206


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 April 10                    (CBET 3462)              Daniel W. E. Green