Electronic Telegram No. 3475
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 G6 (LEMMON)
     An apparent asteroidal object found on Mt. Lemmon Survey images taken by
J. A. Johnson with the 1.5-m reflector (discovery observations tabulated
below) has been found to show cometary appearance by other CCD astrometrists
following its posting on the Minor Planet Center's NEOCP webpage.  H. Sato
(Tokyo, Japan) writes that twelve stacked 30-s exposures taken remotely with
a 0.51-m f/6.8 astrograph of the iTelescope Observatory at Siding Spring on
Apr. 13.5 UT show a strongly condensed and elongated coma of size 6" x 10"
with V-band magnitude 18.7 as measured within a circular aperture of radius
6".5; his ten stacked 30-s follow-up exposures on Apr. 15.4 (taken remotely
with a 0.43-m f/6.8 astrograph at the iTelescope Observatory near Mayhill,
NM, USA) show a strongly condensed coma 10" in diameter with V-band mag 18.6
as measured within a circular aperture of radius 7".6.  L. Buzzi (Varese,
Italy; 0.60-m f/4.6 reflector; Apr. 14.1) writes that his stacked images
show a 9" coma that is elongated toward the north.  J. G. Ries (McDonald
Observatory, 2.1-m reflector + i-band filter) finds a diffuse object in
images from Apr. 14.4 and 15.4 (noting a size of about 6"-8" with elongation
toward the east-northeast on the first night and a coma of diameter
approximately 7" on the second night).

     2013 UT             R.A. (2000) Decl.       Mag.   Observer
     Apr. 13.47575   16 23 13.20   -10 51 30.3   18.7   Johnson
          13.47932   16 23 12.55   -10 51 33.3   18.6     "
          13.48649   16 23 11.22   -10 51 38.9   18.5     "

The available astrometry, the following preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2013-H07.

     T = 2013 July 25.0313 TT         Peri. = 215.6357
                                      Node  =  44.5667  2000.0
     q = 2.049203 AU                  Incl. = 124.1232


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 April 16                    (CBET 3475)              Daniel W. E. Green