Electronic Telegram No. 3070
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/2012 F6 (LEMMON)
     An apparently asteroidal object discovered by the Mount Lemmon Survey
(discovery astrometry tabulated below), and posted on the Minor Planet Center's
NEOCP webpage, has been found to show cometary appearance by other CCD
astrometrists.  P. Birtwhistle (Great Shefford, Berkshire, England; 0.40-m
f/6 reflector; Mar. 23.9 UT) finds the object to be diffuse, with a FWHM of 7"
(double that of nearby stars) in not-very-good conditions; stacked images show
the object to appear elongated with diameter 5", extending to 9" in p.a. 270
deg.  Birtwhistle's follow-up images from Mar. 25.0 in better conditions show
the object to be slightly diffuse and slightly extended with maximum dimensions
9" x 4" (elongated in p.a. 270 deg), with the center of light offset slightly
to the east.  L. Buzzi (Varese, Italy, 0.60-m f/4.6 reflector; Mar. 24.24-24.99)
reports that stacked images reveal a softer appearance on the object's eastern
edge with a possible extension in p.a. around 12 deg in non-optimal conditions.
Forty stacked 40-s exposures taken by R. Holmes (Ashmore, IL, USA, 0.81-m f/4
astrograph) on Mar. 25.2 are found by L. Buzzi, H. Devore, S. Foglia, and T.
Vorobjov to have a 5" coma with a tail 10" long in p.a. 120 deg.  H. Sato
(Tokyo, Japan) writes that four stacked 120-s images obtained remotely on Mar.
25.34 with a 0.51-m f/6.8 astrograph at the RAS Observatory near Mayhill, NM,
U.S.A., show a coma 10" in diameter that is elongated toward p.a. 110 degrees.

     2012 UT             R.A. (2000) Decl.       Mag.   Observer
     Mar. 23.20607   10 03 09.28   +24 45 26.4   20.7   Gibbs
          23.21412   10 03 08.89   +24 45 25.9   20.6     "
          23.22222   10 03 08.38   +24 45 25.7   20.6     "
          23.23030   10 03 07.95   +24 45 25.8   20.8     "

The available astrometry, the following preliminary parabolic orbital elements
by G. V. Williams, and an ephemeris appear on MPEC 2012-F88.

     T = 2013 Aug. 11.1764 TT         Peri. = 281.9162
                                      Node  = 325.6842  2000.0
     q = 1.738106 AU                  Incl. = 114.5423


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 March 26                    (CBET 3070)              Daniel W. E. Green