Electronic Telegram No. 3670
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/2013 TW_5 (SPACEWATCH)
     [Editor's note:  this replaces the text on CBET 3669 (elements).]
     T. H. Bressi reported his discovery of what was initially taken to
be an asteroidal object on 80-s CCD exposures obtained with the Spacewatch
1.8-m telescope on Oct. 3.5 UT (discovery observations tabulated below) in
twilight, with Bressi not noting any cometary appearance at the time, and
it was posted on the Minor Planet Center's NEOCP webpage then; but follow-up
images by Bressi on Oct. 4.5 showed a short tail extending 6" in p.a. around
315 degrees.  Follow-up images with the same telescope by R. S. McMillan on
Oct. 5.5 show red mag 19.0 and a 7" tail in p.a. 315 deg.  H. Sato (Tokyo,
Japan) also reported that the object showed a strongly condensed coma of
diameter 8" with a hint of a tail 15" long toward p.a. 295 degrees on eight
stacked 60-s images obtained with an iTelescope 0.43-m f/6.8 astrograph
located near Mayhill, NM, U.S.A., on Oct. 5.5 and 6.5.  Despite the object
being clearly reported as a comet prior to announcement, the MPC
inadvertently assigned the minor-planet designation 2013 TW_5 to this object
on MPEC 2013-T47.

     2013 UT             R.A. (2000) Decl.       Mag.   Observer
     Oct.  3.49306    9 04 34.47   +26 31 46.6   19.6   Bressi
           3.50623    9 04 34.96   +26 31 43.8   19.7     "
           3.51916    9 04 35.42   +26 31 40.8   19.8     "

The available astrometry, the following very preliminary elliptical orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2013-T92.

     T = 2015 Sept. 9.5716 TT         Peri. = 268.2083
     e = 0.513740                     Node  = 313.9062  2000.0
     q = 3.054386 AU                  Incl. =  39.4728
       a =  6.281385 AU    n = 0.0626067    P =  15.74 years


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 October 12                  (CBET 3670)              Daniel W. E. Green