Electronic Telegram No. 3318
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 168P/HERGENROTHER
     Carl W. Hergenrother, Lunar and Planetary Laboratory, University of
Arizona, reports the detection of an additional companion (denoted G) to those
announced on CBET 3295.  Co-added R-band images were obtained with the Kitt
Peak 2.1-m reflector by Yanga Fernandez and Emily Kramer (University of
Central Florida); the data were made available by Beatrice E. A. Mueller
(Planetary Science Institute).  Companion G was detected at the following
separations and position angles from the central condensation of the primary:
Nov. 11.35 UT, 9".7, 168.0 deg; Nov. 12.29, 9".8, 163.9 deg.  On Nov. 11.35,
the companion was diffuse with no apparent central condensation and elongated
towards the anti-solar direction with dimensions of 2".4 by 1".8.  On Nov.
12.29, the companion appeared fainter, with dimensions of 1".8 x 1".5,
elongated towards the anti-solar direction.

     Z. Sekanina, Jet Propulsion Laboratory, reports that the motion of this
additional fragment G is consistent with the separation from the primary
nucleus A at the beginning of September, with a very low velocity of about
0.1 m/s.  The fragment was subjected to a nongravitational deceleration of 15
+/- 1 units of 10^{-5} solar attraction.  Although the accuracy of the results
is not high, it appears that this is the only fragment whose separation dates
back to the first outburst and must have survived for at least 10 weeks.  In
terms of the nongravitational deceleration, this is the only fragment that
rivals fragment B.  Predicted separation distances of component G from
component A and position angles at 0 h ET:  Nov. 29, 12".0, 167 deg; Dec. 9,
12".8, 170 deg; Dec. 19, 13".2, 176 deg; Dec. 29, 13".5, 183 deg.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2012 CBAT
2012 December 1                  (CBET 3318)              Daniel W. E. Green